Board Game Arena

Can someone explain "tournament mode" to me? I started playing with two others in tournament mode but didn't realize that when I started. I was playing Lucky Numbers. I didn't have time to keep playing game after game so I closed my browser and then learn later that was a bad thing to do. I ruined the game for the others. What should I expect if I play a game in tournament mode? I don't want to quit a game before it's over.

That, you have game either.

By elimination (16-8-4-2)
or
By every player against each other (there is x games for you for x-1 players)
or
By swiss system. Depending how it's set.