Android adapters are basically a pattern or bridge between different type of views and the data [datasource from where data coming for that views].
In this above which is the representing the base structure or a high level pattern of adapter pattern.
Adapter is the mediator which make the view data which we basically representing to the end user in managed way. For example if we are showing a list of 5000 question directly to user, first thing to load such huge data for anroid device is pretty heavy. To manage huge data display what we used to do is pagination. So to manage that android api provided the different type of adapter | views. Probably it's not that easy to give explanation of all type of views. I will suggest to read the documentation to know more about views.