Hmmmmmmm
Well, a regular "Loaf" of sliced bread is generally called a Loaf.
Really long thin unsliced loaves like some French and Italian breads come in, are sometimes called "sticks".
What is often referred to as a "roll" here, may also be called a "bun" and is generally a single person's serving of bread.
A larger round of some types of French and Italian breads can be called "loaf", "round" or even "cake" of bread.
I'm sure there are many other references used in different parts of the country, and by different cultures within the country.
Pita bread, tortillas, unleavened bread and many other more traditionally named breads from the "Old World" are used here extensively as well.