The MacBook is the most difficult Apple laptop to identify. While the MacBook Air and MacBook Unibody are easy to distinguish, differentiating between the plastic MacBooks is challenging. Unfortunately, Apple printed the same model number on all machines, regardless of their internal configuration.
The standard MacBook model came in a white plastic enclosure, while the high-end model was also offered with a black enclosure.
A completely new design was added to the family in January 2008 with the release of the three pound MacBook Air. The MacBook Air, touted as the world's thinnest notebook, featured an aluminum enclosure. To create an incredibly thin and light machine, Apple made a number of compromises, including omitting the optical drive, using a 1.8" hard drive (normal is 2.5"), and integrating the RAM into the logic board, preventing future RAM upgrades.
After more than two years and numerous incremental upgrades, Apple announced a completely new MacBook model in October 2008, the MacBook Unibody. The MacBook Unibody is a hybrid of the original MacBook and the MacBook Air, packing all the features of the MacBook into a more stylish and lighter weight aluminum enclosure.