I took karate classes as a kid, but I don't know much about it.
Well Karate was introduced to Japan in the early 20th century.
Oh, I thought it would be earlier, IDK why.  
Before being introduced to Japan, Karate originated in the Ryuku Kingdom which was annexed by Japan in 1879.
Ahh, gotcha. Are there different types of practices of karate?  Or is it all basically the same?
in English the word "karate" began to be used in a generic way to refer to all striking-based Asian martial arts. Karate schools began appearing across the world, catering to those with casual interest as well as those seeking a deeper study of the art.
Shigeru Egami, Chief Instructor of Shotokan Dojo, opined that "the majority of followers of karate in overseas countries pursue karate only for its fighting techniques ... Movies and television ... depict karate as a mysterious way of fighting capable of causing death
Karate
The Ryukyu Kingdom was annexed by Japan in 1879. Karate was brought to the Japanese archipelago in the early 20th century during a time of migration as Ryukyuans, especially from Okinawa, looked for work in Japan. It was systematically taught in Japan after the Taishō era. In 1922, the Japanese Ministry of Education invited Gichin Funakoshi to Tokyo to give a karate demonstration. In 1924 Keio University established the first university karate club in mainland Japan and by 1932, major Japanese universities had karate clubs. In this era of