Where to get the theory on working with data from the Internet in Android?

Question

Android

Good afternoon,

A little theory is needed:

There is a catalog of goods - name, photo. On the server, I unload it in xml on the "parse" phone, I display this file in the listview - right? Or is there a better and easier and faster option?
Now there are 3 pages (list of cities, list of stores, info about the store) and each has its own Sax parser, which is kind of tedious.

What are sockets for? Those. for what purposes is it rational to use?

If in the future I need to implement a kind of "messenger" for messaging within the application - which technology should I use? Or so to store the list of messages in a file?

Answer 1

Read, maybe
habrahabr.ru/company/mailru/blog/185696 will help