I learned mostly C++ in college and just recently self taught myself Java and Android programming. However I only know how to make standalone applications. What do I need to learn/study in order to have apps between users communicate with each other? 3 things I am looking for. 1. How to download SQLite database or other information to update my database from an online source without including it in my app. This will reduce initial app size and allows me to update databases on the fly without having to update the entire app everytime I want to make a change. 2. Server side programming. I want to learn how to do Client/Server interaction. I can see many benefits to this... 3. Create account from app , Store details from server with ability to sign in and out, get and send data from server. I am a noob in web design/ web programming but I am willing to learn. I just need to be pointed in the right direction. Books. Resources. Even a keyword at least to figure out what languages I need to learn to make my ideas possible.