Autocross is a relatively cheap form of racing with higher speeds than a Motorkhana with the use of mainly 2nd/3rd gear, and no reversing.
Chicanes are used to keep speeds down on longer straights.
Autocross is an ideal environment in which to learn or improve car control skills. A circuit is laid out using plastic cones on a large grass or sealed area, whereas the winner is the competitor with the fastest overall accumulated time from normally 3 runs. You race individually, with another car starting 30 seconds or so behind you with 2-3 cars on the track at once but well separated. Usually there will be at least 3 courses, with 2 runs at each course with your best time out of the 2 counting.