Can someone tell me more about tai chi?

i have seen people practice in the park and i have seen fearless and i think that was tai chi. was it? and how about there was a man that i found on youtube that is a tai chi fighter can somene tell me who he is. ther was atribute to him and i think he still does movies in some capacity.

here
http://en.wikipedia.org/wiki/Tai_chi_chu...

Hi, tai chi (chuan) is a soft martial art as well as a health and meditation system. As a martial art it relies on the angles and direction and neutralization of attach rather then a brute force to suppress an attacker - which i guess would make it a self defense system. As a system of meditiation it urges you to develop softness and flow in order to deal with the life's afflictions in the most effective way. As a health system it advises relaxation - of the body, as well as the blood vessels inside the body which has a tremendous benefit in a long run...

You should read the wiki article already mentioned but if you want a short answer Cutedervish's is pretty good though I do have one bone to pick: Tia Chi Chuan is not a soft style but rather an Internal style, and yes there is a difference. All Internal styles will have as a main focus the cultivation and direction of Chi (Ki in Japanese, I don't know the Korean or any other equivalent words) but not all internal styles are soft. Hsing I Chuan is a good example of an internal style that is hard. Aikido and Judo are often practiced as external styles but are basically soft. Tia Chi has elements of both hard and soft