For their intended purpose, netbooks are a great choice. They aren't powerful enough to do everything you need a PC to do, but are rather meant to be companions to your main PC. Small and light enough to carry around all day, they're the perfect device for taking notes in class or surfing the Web on a commuter train. A typical netbook weighs about 3 pounds or less and has a screen size of 6 to 10 inches. Most cost around $300 to $400.
If you're seeking a new primary PC, you'll want to look elsewhere. Netbooks' limited screen resolutions (10-inch netbooks typically top out at 1280 by 768), RAM, and processing power make editing photos and spreadsheets a pain. In addition, some Web pages, Flash games, and applications simply don't fit well on a small screen. Still, there's something to be said for a system with a battery life of 6 or more hours; in our PCWorld Labs tests, that's how long most of the newest netbooks last.
Most netbooks are based on Intel's Atom line of processors. These chips can run the standard Windows operating system you're accustomed to and all your usual applications, but they're not very fast compared with more-expensive Intel CPUs such as the Pentium Dual-Core and Celeron found in ultraportables, or the Core 2 Duo and Core i5 found in all-purpose or desktop-replacement laptops. Couple this limitation with the fact that netbooks typically have only 1GB of RAM (very few offer 2GB as an option), and you're looking at pretty slow performance.
A netbook is fine for simple Web browsing or word processing, but it struggles on streaming video, editing photos, or running multiple applications simultaneously. And if you're thinking of playing 3D games, forget it: The majority of netbooks use Intel's integrated graphics chips, and not very good ones, at that. Some netbook models may have one of nVidia's Ion GPUs (graphics processing units), which are a lot better at handling graphics and decoding video, but even these won't play the latest and greatest games well, especially in combination with the low-power Atom CPU and limited RAM. Alternatively, some netbooks now supplement their Intel GPUs with a Broadcom decoder chip that does nothing but speed up video playback and improve its quality; if you want to use your netbook to watch a lot of Hulu or YouTube videos, you may want to pay a little extra for this option if it's available.
One more drawback: Netbooks almost never have an optical drive, so you can't play DVDs or load software off a disc without buying and using an external, USB-attached DVD drive.