Hello to all the dear readers, this time we are presenting to you all a revised edition of CEV handout that can guide you when you are having your exams, when you want to do something new either related to your engineering branch or any abstract topic and also when you are getting bored. This handout believe us will surely help you out in many deliema henceforth. Loaded with a numerous sources of knowledge and entertainment this handout has huge potential to save your precious time from searching the best for you out of thousands of options available.
This handout contains websites and portals that you need to start today, internship sources, educational websites, applications, cool websites, movies, books, branchwise societies, courses, open source softwares, stores, fests, youtube channels and finally a note to start your engineering life. ENJOY!
Here are some definitions of API from various resources:
“In computer programming, an application programming interface (API) is a set of subroutine definitions, communication protocols, and tools for building software. In general terms, it is a set of clearly defined methods of communication between various components.” -[Wikipedia]
“An application program interface (API) is a code that allows two software programs to communicate with each other.”-[TechTarget]
Not only these if you search on any website about API, they will explain it brilliantly,
But it is only understandable by those who have worked on API, but if you haven’t then it can be difficult to fully understand, although the explanation is perfect but not in easy words.
The goal of this blog is simply to make you understand the meaning of API in more easy words.
So let’s begin with an easy example-
Suppose if you wanna book a ticket of a train, then it is possible to book tickets of the same train through various apps say IRCTC Official App, Paytm etc.
Now the main thing you need to understand is that how it is possible to book the same seat through two different Apps?
Yes, the answer lies in API.
What API is doing is just letting you use someone’s else code in your application.
Absolutely, PAYTM will be using API provided by IRCTC.
Take a look at this perfect video provided by Mulesoft:
I think you are now getting some idea of what API actually is?
Let’s look at another example- Google is a huge website and it writes a tall pile of codes. These codes are for various services like search, youtube, Gmail, etc. What if we want to use them?
You must have seen, many websites provide logging in through Google’s Login credentials in their apps. So in a second, you can log in on that third party app using your google account.
So what actually is happening behind this, third party-app is using Google’s API for providing login. In easy words, they are using Google’s code for the login system and fitting in their app and using their features, without worrying about what they have written.
Types of API:
Since this topic is very much wide…
Among all the types mentioned above , we will mainly focus on Web APIs aka Web-Services.
Web API as the name suggests, is an API over the web which can be accessed using the HTTP protocol. It is a concept and not a technology. We can build Web API using different technologies such as Java, .NET etc. For example, Twitter’s REST APIs provide programmatic access to read and write data using which we can integrate twitter’s capabilities into our own application.
Types Of WEB-APIs:
SOAP was designed back in 1998 by Dave Winer, Don Box, Bob Atkinson and Mohsen Al-Ghosein for Microsoft Corporation. It was designed to offer a new protocol and messaging framework for the communication of applications over the Web. While SOAP can be used across different protocols, it requires a SOAP client to build and receive the different requests, and relies heavily on the Web Service Definition Language (WSDL) and XML:
Early on, SOAP did not have the strongest support in all languages, and it often became a tedious task for developers to integrate SOAP using the Web Service Definition Language. However, SOAP calls can retain state, something that REST is not designed to do.
Before going to the next type, let’s understand a new term ,
RPC- “Remote Procedure Call (RPC) is a protocol that one program can use to request a service from a program located in another computer on a network without having to understand the network’s details.”
Apart from this definition, we can take it as a protocol working on the client-server model, without going much into detail
On the other hand, Remote Procedure Calls, or RPC APIs, are much quicker and easier to implement than SOAP. XML-RPC was the basis for SOAP, although many continued to use it in its most generic form, making simple calls over HTTP with the data formatted as XML.
However, like SOAP, RPC calls are tightly coupled and require the user to not only know the procedure name, but often the order of parameters as well. This means that developers would have to spend extensive amounts of time going through documentation to utilize an XML-RPC API, and keeping documentation in sync with the API was of utmost importance, as otherwise, a developer’s attempts at integrating it would be futile.
JSON was then developed to provide a simple, concise format that could also, capture state and data types. Yahoo started taking advantage of JSON in 2005, quickly followed by Google in 2006. Since then JSON has enjoyed rapid adoption and wide language support, becoming the format of choice for most developers. You can see the simplicity that JSON brought to data formatting as compared to the SOAP/ XML format above:
So, JSON presented a marked improvement over XML.
Now the most popular choice for API development, REST or RESTful APIs were designed to take advantage of existing protocols. While REST can be used over nearly any protocol, it typically takes advantage of HTTP when used for Web APIs. This means that developers do not need to install libraries or additional software in order to take advantage of a REST API. REST also provides an incredible layer of flexibility. Since data is not tied to methods and resources, REST has the ability to handle multiple types of calls, return different data formats.
Unlike SOAP, REST is not constrained to XML, but instead can return XML, JSON, or any other format depending on what the client requests. And unlike RPC, users aren’t required to know procedure names or specific parameters in a specific order.
I think uptill now, the question “what the hack is API?” is somewhat answered, but this description is not enough , there are many things you still need to explore on your own. So keep exploring.
Thanks for reading..
Happy Learning! ..
*Most Welcome to questions and doubts in comment section……….
Postman -Best app for checking and analysing Web APIs.
While driving a car have you ever wondered how does the engine drive the wheels? How only one engine drives all the wheels of the car? How does the system manage to transmit the power to the wheels? Let’s have a brief look under the hood and understand a very important concept of an automobile, that is “DIFFERENTIAL”.
Engineering of an automobile is a very vast subject. On an average, about 30,000 parts are used for the manufacturing of a single car. Hence to study automobile, the whole subject is divided into 6 major systems: Chassis, Engine, Transmission, Steering, Braking, Suspension. Differential is a part of Transmission system.
Main aim of transmission, as the name suggests is to transmit the power produced by the engine to the wheels so that the vehicle moves. A transmission in general consists of an input shaft, an output shaft, gears and a differential. The input shaft gets power directly from the engine, which is manipulated according to our needs by gears and finally the output shaft carries the final power.
The differential then comes into action. The differential transmits the the power produced by the output shaft sideways.
As shown in the picture, the differential is situated between the two wheels and it transfers the motion of transmission shaft/output shaft to the rotary motion of the wheels. The transmission shaft rotates the driving pinion, which in turn drives the ring gear (crown wheel). This ring gear is attached to a small sun gear/side gear. This side gear is meshed via the differential pinion gear(planet gear). Both the side gears are connected to the half shafts(axle) connected to the wheels.
Why to use the side gears pinion assembly when we can directly connect the ring gear? Also this work seems to be easy. But this is not all a differential does. A differential is designed for a far more greater purpose.
Whenever an automobile turns, there is a difference in the speeds of the inner and the outer wheels.
As you can see, the outer wheel of the automobile has to travel a larger distance than the inner wheel in the same amount of time while turning. Hence the speed of outer wheel is more. This can be achieved by unequal and proportionate distribution of power to the wheels. The outer wheel needs more power than the inner wheel and this unequal but proportionate distribution of power is done by the differential.
The inner half shaft in the figure indicated the part of the shaft connected to the inner wheel while the outer half shaft to the outer wheel. Both the shaft move in anticlockwise direction when moving on a straight road. Hence the power is distributed equally and both the side gears hence the shaft rotate at same speed.
While turning, both shafts do rotate in the same direction. The outer wheel has to move at higher speed than the inner wheel. This produces a couple moment at the differential pinion. This force drives the pinion gear to rotate. Due to this rotation, the side gear of the outer shaft rotates at a rate higher than the inner wheel. The side gear of outer shaft gets an additive rpm while the inner shaft gets a subtractive rpm. Hence due to this production of different speeds in both the wheels, the system is called a differential.
Hence for different turns, different torque is applied on the differential pinion and according powers are provided to the wheels. This was the basic information about differential and transmission. Further the differentials are classified into different types differentials like open differential, locking differential, limited slip differential, electronically controlled limited slip differential, torque vectoring differential etc. But for basic understanding of the differential, this much knowledge is enough.
Quizzes are the best way to verify ones own knowledge and also lean about the unknown topics. Hence at CEV, we organized a quiz competition on 16th March 2016. The quiz was conducted on various topics like general knowledge, movies, books, latest technology, general aptitude etc.
We would like to thank all the participants for taking part in the quiz.
Sketching is an art to put down your emotions, your surrounding or anything that allured you.
It is a very effective way for expressing your emotions.. Sketching varies from being the one a professional artist does in preparation of his painting or a random doodling with no end goal. It is also used in a form of concise rendition with a very impactful presentation of a social awareness message.
It is an art with no rules.. Where no one can make any mistakes. Because rather than going into the specifics the essence of the element matters.
Basically there are three types of sketching:
They are not as complex as their names suggests:
Croquis sketch is used in order to remember the scene or a person in a more permanent type of way. Nowadays fashion designers use this term for the quick sketch of a model.
Pochade sketch is used to capture the atmosphere i.e. the fleeting effect of the light etc. As opposed to Croquis which is a line art Pochade deals more with the shade and atmosphere of the scene.
Portrait sketch is used for the artistic representation of a person with predominance given to its expression.
Conventionally it is done by using different kinds of pencils for example the professional graphite pencils (h, 2h, 3h, hb, b, 2b, 4b, 6b) and even charcoal and carbon pencils. But again it can be done using pens, ink, water colours, oil paints, pastels etc. Here the grade ‘h’ defines hardness and ‘b’ defines blackness. The ‘h’ grade pencils are hard and smudge-free so they are predominantly used for technical drawings and light sketches. The ‘b’ grade is used by the artists for brush-like expressions and smoother look.
Predominantly the sketch comprises of 5 types of strokes.
The different types of shades are created simply by using different type ‘b’ grade graphite pencil. This shades is done by adding layers of the strokes one after the other.
As mentioned earlier there are no specific rules for sketching. But there are few techniques for a beginner to make this experience easy and delightful!
Use appropriate materials.
Choose the pencil according to the type of the sketch. The ‘h’ grade pencil are hardest and used for non-bendable lines. They are mostly used in industrial drawing.
The ‘b’ grade pencil are softer and smudge easily. Hence they are used for making smudges lines and shading your drawing.
Fine art paper can be used for your sketch rather than the smooth one… As it gives nice texture and improves the overall appearance.
Choose a subject.
For a beginner it would be better if you use an object or an image as a base for your sketch. It’ll make it much easier than imagining it.
If you are using a physical object, than take a few minutes to observe the object thoroughly. Notice it’s source of light, make the sketch lighter and darker with accordance to the effect of the light . See if the object is in motion and make the sketch in its accordance. If it helps first visualise it in the form of primary shapes (Square, Triangle, circle etc.) and use them as a base to get the dimensions right.
If you are using an image then divide the image in equal 4,9,25 or so parts according to your convenience. Then replicate each smaller part in your drawing paper as dealing with the smaller part is much simpler than dealing with the whole. It even helps in getting the dimensions right!
Don’t draw heavily
Use light strokes whenever you are sketching as usually it’s a base draft of an image. Therefore always use light and lot of short quick strokes. Using light strokes even helps in erasing the mistakes.
Next step use darker pencil
Once after completing the rough primary sketch, use darker (6b) pencil to define the strokes more precisely and adding details to them. This strokes are also used to get the inner details right. If you want a smoother final product u can always smudge it with the help of cotton or soft cloth.
Erase all the extra smudge prints
Usually while using softer pencil you’ll notice smudges on the paper. So remove all this smudges by using a soft eraser lightly. Keep in mind to use a soft eraser as a putty one might tear the page.
Perfect your lines.
Add further details and repeat the earlier steps with them until you a satisfied with the end result. Many times the soft border gives an unprofessional look to after erasing the extra smudge u can highlight the sketch using a harder pencil (H grade).
You have your beautiful sketch ready.Now you you wish you can spray fixative so that the sketch is preserved and is avoided from smudging
Sketching is not that hard as people seem to believe. There are no right and wrong in it. Above mentioned technique just makes it simpler so use them and let yourself indulge in this beautiful experience and let the magic begin!
Google projects tend to have a forward focus. The company pours resources into researching everything. In past the company had come forward with many projects like Google Maps, Google Glasses, Google Goggles, driverless car etc. which have changed the life and made it easy.
Similarly some of the new upcoming popular projects that Google is putting resources into development are:
The smartphone is one of the most empowering and intimate objects in our lives. Yet most of us have little to say in how the device is made, what it does, and how it looks. And 5 billion of us don’t have one. What if you could make a thoughtful choice about exactly what your phone does, and use it as a creative canvas to tell your own story?
With this idea, Google came forward with the Project ARA. Project ARA is the codename of an initiative that aims to develop an open hardware platform for creating highly modular smartphones. The platform will include a structural frame or endoskeleton that holds the smartphone modules of the owner’s choice such as a display, camera, speaker, processor or an extra battery.
The project was originally headed by the Advanced Technologies and Projects team within Motorola Mobility while it was a subsidiary of Google and was working in collaboratively with Phonebloks. Although Google had sold the Motorola to Lenovo, it retained the project team.
ARA smartphones are built using modules inserted into endoskeleton frames which will be the only component in the ARA smartphones made by Google. The modules that are attached to the frame by electro-permanent magnets can provide common features such as camera, speakers, display, etc. as well as some specialized features like medical devices, printers, projectors, night vision sensors or game controller buttons.
Google wants Project ARA to lower the entry barrier for phone hardware manufacturers so there could be “hundreds of thousands of developers” instead of the current handful of big manufacturers. This would be similar to how the Google Play Store is structured. Lowering the barrier for entry allows many more people to develop modules. Anyone would be able to build a module without requiring a license or pay a fee.
One of the big problems with the wearable devices right now is inputs–there’s no simple way to control these devices. Also at a time when most gesture–sensing technology is unreliable and clunky, Project SOLI, one of Google latest cutting–edge experiments from its ATAP group, provides an enticing example of the type of powerful motion controller that could actually change how we interact with everything from smart watches and tablets to appliances and other everyday objects.
Unlike gesture control tech that came before, Google unveiled an interactive sensor that uses radar to translate subtle hand movements into gesture controls for electronic devices. The sensor is able to track sub-millimeter motions at the speedy rate of 10,000 frames per second and with exceptional accuracy. Not only that, but it fits onto a fingertip sized chip and can be used in everyday devices.
Using radar is a fundamentally different approach to gesture tracking because unlike camera-based system which uses a lens, the radar used in Project SOLI will travel through certain materials, making it possible to place chip inside devices and out of sight.
The basic working principle of the system is that it beams out a continuous signal that gets reflected by arm so it measures the difference between the emitted and received signal. It’s a very complex wave signal and from that the system provides signal processing and machine learns the technique to detect the gestures.
The gestures chosen by the team while tests were selected for their similarity to standard action we perform every day. For example, rubbing thumb and finger could be used for volume control,swiping across the side of a closed index finger with the thumb could be used for scroll across a flat plane, while tapping a figure and thumb together would press a button.
Google’s ATAP department is already testing hardware applications for the technology and we can hope to use this technology in near future.
Till now we have heard a lot about the wearable gadgets and might have even used them but how would it be to make the wearable’s that we can actually wear. Yes! Those days are not far. Google’s new Advanced Technology and Project group is trying its hand at manufacturing high-tech fabrics and wearable electronics that you can actually wear with Project JACQUARD and for this it has signed a partnership with Levi Strauss & Co.
Project JACQUARD makes it possible to weave touch and gesture interactively into any textile using standard, industrial looms. Everyday objects such as clothes and furniture can be transformed into interactive surfaces.
Jacquard yarn structures combine thin, metallic alloys with natural and synthetic yarn like cotton, polyester, or silk, making the yarn strong enough to be woven at any industrial loom.
Using conductive yarns, touch and gesture- sensitive areas can be woven at precise locations, anywhere on the fabric. Alternatively, sensor grids can be woven throughout the textile, creating large interactive surface.
The complementary components are engineered to be as discreet as possible. Google developed innovative technique to attach the conductive yarns to the connectors and tiny circuits of size not larger than a button. These miniaturized electronics capture touch interactions, and various gestures can be inferred using machine-learning algorithms.
These captured touch and gesture data can be wirelessly transmitted to the mobile phones or other devices to control wide range of functions, connecting users to online services, apps, or phone features.
Jacquard components are cost-efficient to produce, and the yarns and fabrics can be manufactured with standard equipment used in mills around world.
Connected clothes offer new possibilities for interacting with services, devices, and environments. These interactions can be reconfigured at any time. Further Jacquard is a blank canvas for the fashion industry. Designers can use it as they would and add new layers of functionality to the designs, without learning about electronics.
Though Google is not the first one to create conductive threads, startups like OmSignal and Sensoria are currently selling shirts and running socks that contains such threads and use their electronics innards to track various metrics associated with physical activity. But Google is trying to combine the radar based Project SOLI with this Project JACQUARD which might be a revolutionary concept.
The alumni of 1965-70, amongst the earliest batches of SVREC had a joyous reunion, remembering their youthful days of college, how they went ahead in life and made their efforts worth its weight in gold! Of the glorious gathering of around 25 alumni , we the current generation of SVNITians had the honour of knowing, hearing and connecting to them through a CEV Talk entitled “Interactive Session by SVNIT Alumni of Batch 1970” on 8th February,2015.
The first talk was delivered by Mr. S. Neelakantan (Retd Scientist ‘G’, Group Dir., Helicopter and Fighter Aircraft DRDO) entitled “Helicopters- Concepts and Development” wherein he discussed about the fundamental concepts & history of Indian Helicopter Technologies, development of indigenously built Advanced Light Helicopters- Dhruv, its design, development tests & certification. Prospects of future advanced warfare & tactical helicopters along with their robustness was also shared.
In one of the most interactive sessions, Mr. Sailesh Lakdawala , Energy Consultant , Duke Energy, USA gave insights on power generation, working and reliability of Nuclear Power. He discussed the current scenario of Nuclear Power Generation in USA, India and rest of the world. This interesting talk also discussed about Fukushima Daiichi Reactor failure, Chernobyl Disaster, Thorium Reactors, Breeder vessels, Small Modular Reactors, Pressurised Water Reactor & Boiling Water Reactors.
In yet another captivating talk, Mr. Harsh Thakkar , Senior Consultant, National Grid USA emphasised the importance of System Protection and also gave us the optimism of honing entrepreneurship skills by giving an example of Green Light Planet , a Forbes 30 under 30 (2012) start-up founded by his son Mr. Anish Thakkar. In end we had an overview of current Elevator Technology by Mr. Satish Mandirwala, Eskay Elevators.
It was heart rendering to interact with alumni who had such diverse backgrounds such as US Navy Weapon Systems, Indian Army, Super Alloy Project, Mining Industry etc.
We thank all the alumni for sharing valuable lessons and ethics important for all to succeed in life. We also extend gratitude to Dr. PD Porey, Director, SVNIT, Mr. Utpal Mistry President & Mr. Kamal Parekh Hon. Secretary of SVNIT Alumni Association for extending their help in making this event a grand success. We also thank all CEVians for working hard to put together a successful informative session and the wide spectrum of audience that came to listen the golden words of wisdom of their alumni.
Everything you need to know about Android, Motorola, Google, Tizen and the future!
Samsung launches Tizen phone in CES 2015 (Though at first sight it’s look like Android phone).
Is this the simple news for you? But it’s not.
Why Samsung needs to unveil a whole new OS based smart phone? Did sell of Samsung Android phone decreases? In market scenario in 2011-12, Samsung is doing good in smart phone market across the world. And keep increasing their turnover. This whole idea of new OS came after the Deal. The Deal between Google Inc. and Motorola Mobility. The Deal worth $12 billion. The Deal which was an investment to dive head first into the smart phone market in US for Google Inc.
After this deal of $12 billion between Google Inc. and Motorola Mobility, Google became smart phone manufacturer as well. And Samsung was afraid that Google might overtake the market and they will be in difficulty. From then Samsung started working on the project called ‘Tizen’ and launches its first beta version on 5th January, 2012 just after few months of acquisition of Motorola Mobility( on August 15th,2011).
“We welcome today’s news, which demonstrates Google’s deep commitment to defending Android, its partners, and the ecosystem.”
– J. K. Shin. President, Samsung, Mobile Communication Division on August 15, 2011 when Google announced an agreement to acquire Motorola Mobility.
We’re just two weeks into 2015, but Samsung’s already made more progress with its in-house Tizen OS. There’s finally a real Tizen smart phone (Open-source but not “The Android”), and the Korean company promises that the rest of the year will bring “a flood of devices” running its operating system. ( Though at this time Tizen Application store is having very few number of apps). Company has claimed that the Tizen-powered smart watches, cameras, TVs, and the new Z1 smart phone that we’ve seen so far are “just the tip of the iceberg”. Tizen will be a crucial part of Samsung’s future IoT(Internet of Things) strategy, helping to connect and smarten up devices and appliances around our homes and beyond. Samsung says it “requires less processing power and memory, thereby ensuring faster device speeds while consuming less energy.” Tizen is being compared with Google’s Android platform. Android is expanding beyond its smart phone origins with tailored versions like Android Wear and Android TV serving the emerging connectivity needs of specific device categories.
Main aim of Samsung for this step might be to diversify away from its dependency on TechGiant Google. And to cut down the monopoly of Google over smart phone OS. The Korean company is keen to make sure that they achieve this, at least in part, through the use of its own software. To encourage developers to jump on board and help build an ecosystem around its anticipated Tizen deluge, Samsung points out that it sold 665 million devices last year, which “could convert into a lot of Tizen.”
Tizen is still far from being able to challenge Android on phones (and it’s doubtful that it’ll ever get there), but the way it’s being positioned and promoted by Samsung in other areas, puts it in direct confrontation with Google’s expansionary plans. No matter how compromiser Samsung’s tone may be, today’s announcement of an expanding Tizen OS is a clear signal of its intent to challenge and compete with Google for the next wave of connected devices.
In short cold war has begun between Google Inc. and Samsung Electronics Pvt. Ltd. It is actually good for customers.
Hmm before I talk about this let me ask you a question. Who has watched the movie “back to the future”? If the answer is yes then good but if it is no then I would recommend you to watch it. Apart from a good story, what the movieportraysis a lot of cool gadgets and the mosteye catchingone is the coolHoverboard.
Well for those of you who don’t know what aHoverboardis, imagine it as a normal skateboard but with no wheels and lifted (or I would say hovering) a few inches above the ground. Long story short it is just like a flying skateboard, sounds cool right!!!
So coming back to the point why I am talking about aHoverboardis because it has actually become a reality. Yes I said it right we have invented aHoverboard, well not we but people working at the companyHENDOhave. No, it’s not a hoax but they have actual proof that theHoverboardworks and to prove it they literally gave it to the legend Tony Hawk to have a ride! A small demonstration can be seen in the pic below.
So how does it actually work? Well the company says that it usesfourhover-engines utilising ‘Magnetic Field Architecture’, to break it down it uses an opposing magnetic field from the surface below. Well in simple terms what the engines do is that they have some permanent or electro-magnets in them with changing magnetic fields . Due to this changing magnetic field eddy currents are produced in the conducting surface below which tends to generate its own magnetism. According to Lenz’s law the field so produced is in opposition to its cause and hencedue torepulsion the board is able to hover. An illustration is given below.
Obviously the technology behind it is very advance with the use ‘Dynamic magnetic suspension’ and ‘halbach array’ etc. Both of these technologies are currently in use in Magnetic levitation trains.
Well one major drawback in these boards is that they require metallic sheets as surface below to actually produce this effect but the company says that they are working on some more compounds. Plus the board comes at a price of a whopping 10,000$ but they do provide a ‘white box’ developer kit at a price of 300$ so that you can get an idea of how the board works and apply it anywhere. The company is open to any new developments suggested by anyone on how to improve their technology…..now that’s cool!!!
Well to sum it all up I can say that the day is not far behind when we could actually use a Hoverboard (literally flying) to move from one place to another .
In this quickly growing world of technology, people have become so addicted to smartphones, tablets, iPods and this entire virtual online world that they sometimes don’t even realize that they exist in a real world. Since these device don’t work on food and water there comes this huge issue of giving power to these devices and thus comes the term charging of the batteries present in these devices and as soon as the word charging comes our head becomes full of tangled wires. So to deal with this, now scientists have developed a new technology for wireless transmission of power. It basically works on a concept called RESONANT INDUCTIVE COUPLING. This concept is very easy to understand so please don’t be scared and astonished by hearing such a complicated term. Actually to understand this concept you only need your 12th std physics. So there are basically three words ‘resonant’, ‘inductive’ & ‘coupling’. Let us revise the meanings of these words in context of physics.
Firstly resonance, in simple words resonance happens when the amplitude of a wave (in this case an electrical signal) maximizes at a certain frequency. In our case this is important as we want to ensure maximum electrical power transfer.
Now electromagnetic induction, in our case we are talking about mutual inductance which in short is just induction of voltage or an emf in a coil when a variable current carrying coil is kept in its vicinity.(of course lesser the distance higher the induction)
Last but not the least coupling is just used as both the coils are electrically coupled (not physically).
So now if you take all these three things together in your mind as one joint concept then I believe your previous review of the term being complicated will change a bit.
Hence by this I guess you can easily understand how power can be transmitted wirelessly and so nowadays whatever wireless chargers you see simply just consist of two coils one is the transmitter and the other one is the receiver. High frequency (resonant frequency) signals are first generated before the transmitter and then after the receiver receives the signal, the signal is rectified to whatever DC output is required for the device.(high frequencies are used so as to decrease the losses through the air i.e to decrease the leakage flux)
There are a lot of advantages as we can see there is no need to deal with the long and tangled wires, and we don’t even have to stay very close to our power sockets.
One more big benefit is that we can simultaneously charge one or more devices with just one setup as you can see in the figure beside-
But on the downside there is also a fact that we have to make a great sacrifice on efficiency as we increase the distance between the two coils the leakage flux through the air increases which in turn decreases the power transferred. Another problem is the range of the distance at which the two coils are kept because after some distance there will be no power transmission but for that a solution that is being proposed is that we create a network of all the transmitter coils at suitable distances so that the receiver can receive power suitably from all the coils.
Also there are alternate options available other than resonant inductive coupling like Conductive Connections, Radio Transmissions and Wi-Fi.