1.The Pizza-Box Case-This is one of the smallest case there is.It got its name because it looks like a pizza bo.You can imagine how this case look like.By the way,it's put down horizontally,just like how you would place a pizza box on a table.This case doesn't provide much space inside either.It probably only comes with one or maybe two drive bay(s) at the most.Although you might not be able to add any adapter cards,this case takes up the smallest amount of room meaning they're useless if your going to put a lot of stuff in it.These cases are typically used for network workstations.I reccomend that you don't buy these cases for home computer uses.

2.The Desktop Case-This case is the same as the pizza-box case except this case is bigger.This case provides two or three open drive bays on the front,wwith one or two closed bays.This case has nough room to hold up to seven or eight adapter cards in the back.This case in my opinion is good for ofice uses more than home computer uses.