netbook
A netbook is a small, light, low-power notebook computer that has less processing power than a full-sized laptop but is still suitable for word processing, running a Web browser and connecting wirelessly to the Internet.
Netbooks fall into a category of what vendors refer to as “small form” computers. Such computers have been known by various names, including subnotebook, ultra-portable, mini-notebook, mini-thin client, cloudbook and ultra-mobile PC. The generic name netbook, however, is currently the most popular marketing buzzword. Typically, a netbook will have a slimmed-down operating system, a smaller-than-usual keyboard, a smaller-than-usual screen and very little (if any) storage space.
Initially targeted at the education market or consumers who might want a second computer, netbooks are gaining a broader consumer base now that budgets are tight and consumers around the world are starting to feel comfortable using applications and media in the cloud. In 2009, netbook sales increased more than 100% over 2008.
Learn More:
Intel blogger Paul Bergevin foresees two markets for netbooks.
Wikipedia maintains a comparison table for netbooks.
Matt Buchanan at Gizmodo takes a stab at defining all the names vendors use to describe small notebook computers.