Android-questions

Difference between Activity and Fragment ?

How to handle rotation and save data using Fragments ?

We have 3 activities and buttons in each activity, after we reach the 3rd activity we press the back button, so what happens in the activity stack ?

What is MVVM and MVP?

What are the advantages of MVVM ?

What happens when you remove an item in recycler view ?

Why FlatMap operator in Rx-java ?

Why View model in MVVM ?

Have you used room or SQlite ?