Difference between Laptop and Notebook computer

Some computer companies call their computers laptop while others prefer to call their mobile computers as notebooks. So what is the similarity and difference between a laptop and a notebook? Sun explains:

"Laptop computers are somewhat larger than notebooks and will accommodate a built-in disk drive unit and, optionally, a floppy drive unit. That is, a CDROM drive is either built into the unit or the unit has a built-in bay that will accommodate a removable CDROM drive.

Notebook computers, on the other hand, will allow you to attach, via cable, a CDROM drive. Since the drive is not built into the unit, notebooks are smaller and lighter than laptops. Hence, a notebook is an ultra-small laptop. Another way to look at it is a notebook is about the size of (or a little larger than) a real binder notebook." via