Video streaming means sending films, shows and live sport over the internet to an app on a phone, a smart TV or a laptop, which plays the video while it is still arriving. Nothing has to be downloaded first. In India, streaming services are usually called OTT services. OTT stands for over-the-top, because the video travels over an ordinary internet connection instead of a cable or a dish.
Imagine the last over of an IPL final. Tens of millions of people are watching the same ball at the same moment, on phones in buses, on TVs in living rooms and on laptops in hostels. Many of them joined only in the last few minutes. Every one of them expects the picture to keep playing. Each of them also sees ads between overs, and some see different ads from their neighbours. Several layers of software make this possible, and different companies build most of them.
The first layer is the OTT platforms, the services and apps that viewers see. The best known is the streaming service, which sells films, shows and sport by subscription, by ads, or both. The smart TV operating system is the software on the TV itself, and it decides which apps appear on the home screen. Apps made only for the phone sit in this layer too, such as the live streaming app with virtual gifts and the micro-drama app.
The second layer is video delivery technology, the chain between the studio and the screen. A video encoder compresses each film into several copies at different qualities. Servers in many cities, called a content delivery network (CDN), keep these copies close to viewers. The video player inside the app picks the right copy as the viewer's network speeds up or slows down. This method is called adaptive bitrate streaming. It is why the picture turns blurry for a moment instead of stopping. Other products in this layer insert ads, prevent piracy and measure the quality of every stream.
India is one of the largest streaming audiences in the world, and its prices are low. Many viewers will not pay a subscription, so ads matter more here than in richer countries. The page on AVOD, SVOD and TVOD explains these ways of paying. Above all, live cricket brings in viewers like nothing else, which is why sports media rights are so expensive. The hardest technical moment is the one in the final over, when everyone arrives at once. The page on high concurrency explains why.