What is the difference between slalom and 4x(Mountain Cross, Four-Cross)? which ever one you call it.

in slalom there are 2 people, each whith their own gates to go around. In 4x it is 4 people racing each other no gates, larger jumps usually

Slalom is also two individual courses. You are on seperate tracks (at least from what I have seen)...4x is like boarder cross, everyone on the same course.

In the really old school Dual slalom races, there were a couple of races where the riders were on the same track, this has been changed now because they used ro actually go out of their way to basically take the other rider out.