When you’re starting out with Android development, and even as an expert, you will hear about a lot of different architecture patterns. Anything from:
It can be extremely hard to know which one to pick, what their differences are, and why they matter. I will tell you that even with my three years of Android experience at the point of writing this, I have trouble answering the first two questions. I can, however, explain why these architecture patterns matter - and it boils down to the idea of separation of concerns.