I am new to the topic of alliances. I am experienced in the game, but I haven't played in over 6 months. In that time, the topic of alliances has been introduced and I was supposed to build some banner. I was invited by many alliances and I accepted one. Then I saw something containing alliance wars. Our alliance was marked at rank 27 and we had like 5000 points. Then it said there was a timer of 5 days 5 hours and the next round would start then. I understood nothing of what was written in that window. So I want to ask these questions:

1. What is the purpose of alliance?

2. What are these war points and ranks?

3. What happens in alliance wars? Do all compound leaders of an alliance gang up and kill the opposing team or something?

4. What is the alliance banner?

5. I have noticed something about certain ranks and raids receiving fuel. Like I went in the alliance page and I saw like a little picture of a fuel can and it said: Total Booty- 10 fuel and underneath there was a button saying "Claim Fuel". I clicked it and I magically got 10 fuel added to my inventory. What happened here? I know there was some prize but what is the reson behind this prize?