Why do we create a channel for casting content and what contents can be added into a channel?

We create a channel to display our self generated contents in a chosen layout with dimensions. It is meant for a systematic visual representation of the added contents in a chosen layout. These dimensions in a layout is meant for changing the size of the channel on screen. The content which is added into a channel can be in the form of playlists, medias or links. Apart from the layout one can even change the channel cover and preview it before casting it on screen. Any such channel can only be casted on a screen which needs to be paired by entering the six character pair screen code. E