When looking for (and buying) a laptop computer, it might be a good idea to get familiar with the vocabulary that describes the many different forms that mobile computers come in. Here are some terms sometimes used for subtypes of laptop computers

UMPCs

These Ultra-Mobile PCs are mobile computers that are similar in size to PDAs. They are extremely portable, to say the least.

Because of their small size, they incorporate a 7 inch or smaller touch-screen for you use as a virtual keyboard. On the other hand, some units are designed with a miniature physical keyboard (”thumbboard”) and mouse interface. They house lower performing, power-saving components (in comparison to larger laptops). Examples of UMPCs are the OQO Model 02 and the Sony VAIO UX Micro PC.

Ultraportables

These are laptops with screens that are usually smaller than 11 inches diagonally. They weigh less than and a weight of less than 4 pounds. Keyboards are usually not full-size. The main market for these units is made up of road warriors and other business travelers who need equipment that is small and lightweight. Ultraportables are often very expensive because of the extreme miniturization. They also have extended battery life, house power-saving CPUs and almost always have integrated graphics.

Thin-and-lights

These laptops usually weigh in at between 4-6 pounds with a screen size of between 12 and 14 inches diagonally. Examples of this variety: the Sony VAIO CR , HP Pavilion DV2000 and Apple MacBook .

Desktop replacement computers

These are the biggest and most powerful laptops. They are meant to be used in a fixed location and not carried around; they are too bulky and heavy. Sometimes called a “luggable laptop.” Because size is not an issue, they have more room for powerful components and a bigger screen — 15-20 inches in most cases.

Desktop replacements tend to have limited battery life, usually not more than 3 hours. This is because the hardware is not optimized for efficient power usage. An example of a desktop replacement computers are gaming notebooks, which are designed to handle 3D graphic-intensive processing for gamers. These notebooks possess similar features as desktop computers.