Laptop Buying Guide:

If you are going to buy a laptop, the first thing you need to do is figure out which category of laptop best suits your needs. Once you've done that, it's time to examine the specifications. You will have to choose from among a host of options for the processor, RAM, graphics, display, and other features. Deciding what is necessary and what the user can live without is difficult, but it's essential to selecting a laptop you will love at a price you can afford. If you don't understand the specs, you could save money but miss out on desired features and performance, or you could spend too much for things you don't really need.

CPU

The CPU is the heart of any computer, and is responsible for running the operating system and every application. A speedier CPU means faster-running programs, but usually it also means lower battery life and a more expensive laptop. Nearly every laptop has a CPU from either AMD or Intel.

If you're buying a netbook, you'll find that it uses either Intel's Atom line of CPUs, or AMD's Fusion E-series. The Atom line offers pretty slow performance and poor integrated graphics, but the battery life is phenominal. AMD's Fusion E-series chips are a bit faster, with dramatically better graphics and video decoding, but you'll sacrifice an hour or two of battery life for it. Neither choice is powerful enough for the most demaning tasks, like encoding HD video or playing the latest games.

Ultraportable PCs generally use low-voltage AMD or Intel processors. These chips are usually dual-core CPUs that are quite similar to the regular notebook CPUs found in larger laptops, but run at much lower clock speeds 1.2GHz instead of 2.1GHz, for example. Lots of processors--too many to list here--are available in this group. When you're shopping, however, you can follow a few general rules: More cache is preferable, and higher clock speeds are better but will drain the battery a little faster. AMD's CPUs are a bit slower than Intel's, but are priced to move and offer superior integrated graphics. Note, too, that some ultraportables don't use low-voltage CPUs, and are considerably faster (but have shorter battery life) than those that do.

All-purpose and desktop-replacement laptops offer both dual-core and quad-core CPUs in a range of speeds. Intel's Second-Generation Core CPUs (Core i3, Core i5) are excellent for most users; only people who truly require a quad-core CPU (for encoding video, playing games, or running engineering applications, for example) would want a quad-core Core i7 processor. Again, more cache and higher clock speeds are better, but any CPU over 2.0GHz is fast enough to handle all the basic stuff, such as playing music, browsing sites and playing Web games, displaying online video, and managing e-mail.

You'll also find laptops with AMD processors. AMD's new Fusion A-series processors aim to offer better value in affordable all-purpose and ultraportable laptops. While the CPU part of these processors aren't as fast as Intel's, the graphics portion is far superior. What's more, the battery life stacks up well against Intel's processors. This wasn't the case with older AMD processors, which ate through your battery a couple hours faster than Intel's.

Graphics

The graphics processing unit in a computer is useful for more than just playing games. This bit of silicon is ultimately responsible for everything you see on screen, from 3D games to the basic Windows desktop. Perhaps more important for some people, many GPUs can accelerate video decoding: With the latest version of Adobe Flash and the right GPU, Web videos from Hulu or YouTube will run more smoothly and look better.

Most laptops are available with a choice between integrated graphics (from Intel or AMD) or a discrete GPU (from Nvidia or AMD). Integrated graphics are built into either the system chipset or, in newer systems, the CPU itself. They share the main system memory with the CPU. Discrete GPUs are individual chips that are dedicated to graphics and have their own pool of memory, which results in far better performance.

Integrated GPUs from Intel are generally quite poor: They don't run 3D games very well. Second-generation Intel Core chips have dramatically improved video decoding, and the 3D graphics are faster, too. Still, they're too slow more most modern 3D games. AMD's integrated graphics is a significant step up, even capable of playing modern games at reduced resolution and detail. If you want to play games other than the occasional Web-based diversion, you probably want to select discrete graphics. You'll find lots of graphics chips to choose from, but in general the Radeon 6000 series from AMD is faster than the comparable 5000-series models, and the 500 series from Nvidia is speedier than the comparable 400 series. Within each series, the more-expensive models are swifter: ATI's Radeon HD 6850M is faster than the Radeon 6550M, and Nvidia's GeForce 560M is faster than the GeForce 520M, for example.

RAM

Memory is as important on a laptop as it is on a desktop. In fact, because laptop hard drives tend to be slower than their desktop counterparts, it may be more important. The more RAM a laptop has, the less often it needs to load data from the hard drive, after all. It's a good idea to get at least 4GB of RAM if it's offered as an option. Beyond that, the benefits are usually small and the cost to add more RAM is high.

Laptop memory these days is almost always DDR3, which is faster than the DDR2 memory commonly found in laptops as recently as a year ago. You'll also see a clock speed listed on some laptop memory specs, such as 800MHz, 1066MHz; or 1333MHz. The higher that number, the faster the RAM. Spend the money to get to 4GB first, and then worry about speed--if your choice is between 4GB of 1066MHz or 2GB of 1333MHz memory, go with the 4GB of slightly slower RAM: You'll get more performance bang for your buck by doing so.

Display

The size of the display will be determined in part by the type of laptop you buy--by definition, netbooks have smaller displays than desktop replacements. From there, you have several additional factors to consider: screen resolution, LED backlighting, and a glossy or antiglare surface.

Screen resolution is a measure of how many pixels are on the screen, horizontally and vertically. A netbook with a 10-inch screen may offer a resolution of either 1024 by 600 or 1366 by 768, for example; in this case, the screen size is the same, but the latter option will have a lot more pixels crammed into it. That gives the user more space on the desktop and shows more of the Web pages or spreadsheets the user views, for instance. On the other hand, the higher resolution makes all of the icons and text appear smaller, so things can be harder to see. Most users prefer higher resolutions on their displays, but you might want to look at two laptops with the different resolutions you're considering to determine whether you like more desktop space or larger icons and text.

Many laptops have LED-backlit displays. Instead of compact fluorescent tubes, light-emitting diodes sit behind the LCD panel. LED-backlit displays tend to be more energy-efficient, so the battery lasts longer. LED-backlit displays are increasingly common, and now can be found in all laptop segments and on most notebook models, at least as an option.

You'll also notice that some laptops have a very shiny, glossy display, while others have a soft matte finish on their screen. This is a matter of the coating on top of the display. A glossy coating certainly creates a lot more glare, but it also lets light through more easily; as a result, glossy displays tend to look like they have better contrast and brightness. The matte finish on other displays may result in the appearance of a little less contrast, but it also produces a lot less glare. If you plan to use your laptop outdoors or in brightly lit areas, you might want to avoid a glossy display.

Connectivity

Every laptop, from a netbook to a desktop replacement, includes wireless networking. The standard you're most likely to encounter in coffee shops and airports is 802.11g Wi-Fi, and you can't find a laptop these days that doesn't include 802.11b/g support (802.11b is an older, slower networking standard that you don't see much now). That's the good news.

The bad news? Even though the faster, less error-prone 802.11n networking standard is quickly making its way into homes, and most new laptops support the standard, you won't necessarily find 802.11n in coffee shops and airports just yet. It's a good idea to make sure that the laptop you buy has 802.11n networking if you want it to be future-proof, or if your gift recipient wants to take advantage of the 802.11n wireless they may already have in their home. Fortunately, 802.11n-capable laptops can still connect to 802.11g Wi-Fi just fine, and 802.11n hotspots almost universally allow 802.11g devices to connect; the connection will simply be slower than it could be.

If you need to plug your new computer into a wired network, ensure that the laptop you buy has an ethernet jack--most do, but a few netbooks and super-slim ultraportables don't. The standard now is gigabit ethernet, and while some laptops may have slower ethernet jacks (limited to 100 megabits per second), it isn't a major concern. Unless you need gigabit speed to transfer lots of very large files and you're sure you'll be plugging into a gigabit wired network, you don't need to look for that feature specifically.

Many laptops also offer Bluetooth, which is great for making use of Bluetooth mice, keyboards, and headsets, or for syncing contacts and calendar information with a Bluetooth-enabled phone.

Optical Drive

Most all-purpose and desktop replacement laptops include an optical drive, while most netbooks do not; with ultraportables, it's hit-or-miss. All optical drives in laptops these days will play and burn DVDs. Some laptops even include or offer the option to add a drive that can play Blu-ray media and burn DVDs and CDs, which means you can use these models to watch high-def movies. Blu-ray Disc writers--which burn to those high-def discs as well as to DVDs and CDs--remain less common in laptops, and are a more expensive upgrade than the Blu-ray-reader/DVD-and-CD-burner combo. Don't worry too much about the performance ratings on optical drives unless you plan to do a lot of disc burning.

If the laptop you have your eye on doesn't offer an optical drive but you have software on CD or DVD, or if you want to watch a movie on disc, you can buy an external DVD drive that plugs into the USB port. Look for a drive that's "bus-powered"--this means that the drive can get its juice from the laptop's USB bus, and shouldn't need a dedicated power adapter.

Storage

Hard-drive space on a laptop is just as precious as it is on a desktop PC. Netbooks and ultraportables typically don't offer more than 500GB of storage, and lower storage limits are more common. All-purpose and desktop-replacement laptops can have up to a terabyte of storage. You'll see drives listed as 4200 rpm, 5400 rpm, or 7200 rpm, a measure of how fast the platters spin, in revolutions per minute. Generally speaking, the speedier drives have faster data-transfer rates and seek times, which means better file copying, application launching, and boot-up speed. If you plan to store a lot of photos, music, or video or intend to install a lot of big games, you'll want as much hard-disk storage capacity as you can get. Some desktop-replacement laptops offer dual-hard-drive configurations.

Some laptop models provide an option for using an SSD, or solid-state drive, instead of a standard hard drive. SSDs tend to cost a lot more and offer far less space than the regular rotating magnetic-media type, but they're far faster and more durable since they have no moving parts. Some SSDs are even more power-efficient than regular hard drives. SSDs can be a good idea for anyone especially concerned with performance or durability, but you'll pay a lot more money for a lot less storage capacity.