These are different styles of the martial arts. Each has its own good and bad points. My son and I have trained in a few different styles. From karate to kung fu and Taekwondo. Currently we have been doing some MMA training with a local instructor as well as continuing our training in Taekwondo. (my son really loves learning the high jump kicks).
We have found that combinging the different styles has helped us choose the different techniques that have worked for our own body styles.