There are hundreds of karate kata, starting from the very short, that have basic karate moves, to the very advanced karate kata, containing hundreds of techniques, steps,turns,kicks,jumps,strikes,etc.
With the online video capabilities we have today, it is possible to put up full karate tutorials, enabling people to learn karate katas online. From the very basic kihon kata, right up to the black belt kata.
The only downside, is the fact that there is no instructor to correct you. So it is very important to study every detail when trying to learn karate katas online, once you have a kata down, film yourself, then watch your recording side by side, with the kata tutorial.
Karate kata is at the heart of karate practice and to me, it is the most important part of karate.