Actually, there are more than six prohibitions on Yom Kippur, for anything prohibited on Shabbat is also prohibited on Yom Kippur.  For example, on both Shabbat and Yom Kippur, we do not light a fire, we do not write anything down, we do no cooking or baking, we do not carry anything from within our homes to the outside, or anywhere outside, etc.  However, there are six additional prohibitions on Yom Kippur.  They are: 

1. no eating
2. no drinking
3. no leather shoes
4. no bathing
5. no sexual relations
6. no anointing (in a modern context, this means refraining from cosmetics)