Karate originated in the islands of okinowa. “Kara” empty, “Te” hand. There are a variety of different types of Karate: Shotokan, Okinowa Te, Shito-Ryu, Goju-Ryu, Kyokushinkai and more.
Generally Karate skills consist of stances, blocks, kicks and punches. Karate is most useful in the 2 outside fighting ranges: kick and punch range. It is effective at using and defending against kicks and punches.
Karate lacks the locking, choking, grappling and throwing skills of jujitsu and therefore it does not defend against these types of skills. Combining other martial skills into your Karate training is a good idea and will make your art more functional and reality based.