What is Futsal?

Futsal is FIFA's official indoor soccer game which is, essentially, a scaled down version of outdoor soccer played indoors. It is a small sided game (5v5) played on a smaller field (roughly basketball court sized) with a smaller (size 3-4) ball. Futsal is played with touchline boundaries. There are no walls in play. This is the game that outdoor soccer players around the globe play when they are indoors to refine and maintain their control skills and touch.
It is superior to walled soccer in terms of developing better skills and technique. In traditional American walled soccer, players regularly whack the ball (and sometimes their bodies) against the boards which promotes improper technique and too often rewards errant play.
In Futsal, players are constantly reminded to play the same quality control game that is required for success in the outdoor game.