Can someone inlight me ?

I have been playing since yesterday and there I have some questions which I can't figure it out.

1- First of all what is the usage purpose of "SNAP" button on top of the screen ? 
2- Secondly what is the purpose of updating cards ? Just their color changes but there is no power incresement. So what is the point of that ?
3- what is the purpose of the game ?  Game is great but what is the end of it ? I couldn't see clan tab or global tournement. Are we playing just for nothing ? There must be a purpose.
There also should be chat screen, So we can chat with other players and we can help each other in real-time. 

Above all, marketing choices are influenced by visual design. To see results, developing a comprehensive marketing plan is essential. Additionally, having a website https://www.programmingassignment.net/services/html-assignment-help/ is crucial for better product promotion; to do this, hire developers for html assignment help. This will assist in driving up sales and securing the ideal marketing niche.