Futsal is played on a flat, hard surface most similar to a basketball court and sized for 5v5 play. The game uses a smaller and heavier ball than a soccer ball which keeps the ball on the ground more often than in the air
The game is much faster with the flat surface and tight spaces. Certain ball-skill techniques are used in futsal like receiving with the sole, toe poke (a shooting technique), etc.
With these differences, even an experienced soccer player might notice significant differences between the two sports. However, skills developed through futsal complement skills developed in soccer, and vice-versa