One of the newest iterations of portable computers is a notebook like computer that is commonly much smaller than a regular notebook but a bit larger than a common paperback book. It's lightweight not only physically but also in terms of the operating system used. Some will use Linux or XP Home Basic that is stripped down. In some cases, instead of a hard disk drive, the computer will house a solid state disk drive not unlike a compact flash or SDHC non-volatile memory card.
With such a modest foundation, the netbook is aimed squarely at users who depend upon web and/or online applications more than stationary applications that are purchased and dedicated solely for a computer.
Netbooks appeal to users because of its smaller size than today's notebook computers which have steadily grown in size, weight and complexity. They don't try to emulate the desktop computer as the traditional notebook does, but can offer the frequent traveler a usable tool where weight, size and complexity are a premium.
On the face, their cost may be a $100-$200 less than traditional notebooks but they can be equally as expensive as their larger brethren if similarly equipped. Then what is their attraction? Mainly their stripped down models are nimble, small and easy to use.
For the frequent traveler or student, it might make a great lecture hall companion or editing or drafting document tool.