I took Ju-Jitsu a few years back. The following is an exerpt from a website, that gives you a general idea of what Ju-Jitsu is about.
"What is Ju-Jitsu?
Ju Jitsu means 'the gentle way' or 'the gentle art'.
Ju-Jitsu is a full contact martial art and is not to everyone's liking but those who stick it out learn tricks of agility and endurance that few realised they had before and when they first started to train with us.
Teaching starts with learning the basics of falling safely. We do a lot of falling.
The ethos behind Ju-Jitsu is using the power and weight of an aggressor against them. This can be a gentle manipulation or a full force blow or throw - whichever is most appropriate for the situation. Ju-Jitsu does not rely on great body strength, instead our training teaches timing, flexibility, agility and knowledge of the body. Combine all of these techniques and you have the ability to control a confrontational situation as much to prevent injury to the person who may be attacking you as to protect yourself.
The idea is that a defender will yield to then force of an attack rather that opposing it. If an opponent pulls the defender towards him then the defender obligingly pushes forwards rather than pulling back. In this way the force of the attacker is used against the attacker. If the attackers pull was countered by the opponent also pulling then who ever has the strongest pull would win.
Ju-Jitsu encompasses throws, locks striking and blocking techniques and so has a very wide syllabus. A defensive movement may well start with a block against a punch. This would be followed by a diversionary strike. This is not meant to incapacitate the attacker but to give the defender a second or two to apply, perhaps, a throw.
When throwing use can be made of any hard surfaces on which the attacker will land and it may be possible to cause the attacker to land on his shoulder or other vulnerable part of his body."