Throws only. In self defence this means grip contact with your attackers and the possibility of being taken to the ground with them, which is never a good idea. Judo is an Olympic sport, divided into weight categories, it is highly competitive.
Strongly recommended for kids as an entry level into Martial Arts at a young age as it doesn't involved striking. Very good for adults as a hobby or competitive sport, but remember the ground appears to get harder as you get older.

Relationship to Krav Maga

In Krav Maga we use throws and takedowns. Some of these are taken from Martial Arts like Judo and sport wrestling. The use of bodyweight/strength techniques, power, tactics and positioning. However, in Krav Maga we always imagine that the opponent has a knife concealed about them, this helps us to minimise the amount of grappling contact (just in case they are actually armed).