There are two sets of Hammer and Chisels. The first is a Hand set and the other is the Bull set, or Bigs. In each set there are two types of chisels. One is called a Tracer and the other is called a Breaker.
The Bull set is used to break or trace thick pieces of granite. One person holds the chisel while the other hits it with the hammer.

The hand set is usually used on thinner pieces of granite and can be used by one person instead of two

The difference between a Breaker and a Tracer.