Paula throws on a 50 year old Shimpo wheel. Above she throws offf the hump (or mound) which enables a potter to center clay as it is needed. This technique enables making many bowls. Below is a video of Jerry Horning throwing off the mound.
Large or flat clay forms can not be thrown off the mound. Instead they are thrown on a bat. When the plates, below, were thrown, they are allowed to dry and are then flipped over and a foot ring is trimmed into the bottom. Throwing small bowls off the mound doesn't necessitate a bat.