One of the top Brazilian Jiu-Jitsu websites, www.bjj.org describes jiu-jitsu as follows:
Brazilian Jiu-Jitsu is primarily a ground-fighting art. Most techniques involve both fighters on the mat. There is a heavy emphasis on positional strategy, which is about which fighter is on top, and where each person's legs are. Positions are stable situations, from which a large variety of techniques are available to both fighters.
Specific techniques taught are designed either to improve one's position (for example, to "pass the guard" by going from being "in the guard" to getting around the opponent's legs, resulting in side control); or else as a finishing submission. Most submissions are either chokes or arm locks.
Brazilian Jiu-Jitsu is primarily a ground-fighting art. Most techniques involve both fighters on the mat. There is a heavy emphasis on positional strategy, which is about which fighter is on top, and where each person's legs are. Positions are stable situations, from which a large variety of techniques are available to both fighters.
Specific techniques taught are designed either to improve one's position (for example, to "pass the guard" by going from being "in the guard" to getting around the opponent's legs, resulting in side control); or else as a finishing submission. Most submissions are either chokes or arm locks.
bravenet.com