What's the difference between full contact karate and traditional karate?

None of the above is quite right. Full contact is the real fighting, but this is the real sports karate. Traditional karate, such as rigid and soft, Songtao, does have the rule of stopping one inch, that is, stopping one inch without hurting the opponent, but the real traditional karate training is very real sparring, and it is often some deadly tricks, such as finger piercing, dazzling, hand knife and so on. Traditionally, if you really want to learn karate, you should practice traditional karate. Just like wtf and itf in Taekwondo, itf is much stronger than wtf, but full contact also has its advantages. Traditional karate can also be practiced according to full contact, and there is no hard and fast requirement.