Size and Cooling
A laptop is a portable alternative for those computer users always on the move, or simply for those who desire a unit with a smaller form factor. Computer components within laptops are typically not as powerful as the components within large, full-sized desktop computers, due mostly to the fact that the components within laptops must be streamlined and made smaller so as to fit into the much more confined space. Cooling is of course a large concern with laptops, as all computers must stay adequately cooled and make use of fan(s). Specifically with laptops however, components must be optimized to generate little heat, even less heat than desktop counterparts. As such, the smaller components of the laptop need also be more power efficient, as power hungry components can provide dangerous levels of heat within a laptop.
Memory and Speed
Due to the smaller nature of laptops, their components are less powerful because of the necessary streamlining involved. Depending on the model, graphics cards may be less powerful, processing speed of the CPU may be slower, RAM, which lies behind the speed and ability to run multiple programs at once (temporary memory) may be lower, and hard drive space (permanent memory) is also likely to be affected negatively. (Hard drives aren't always necessary, with some newer laptops such as the Macbook Air offering Solid State Drives). Also, unlike desktops, the portable nature of laptops assures that they rely on an included battery to run, unlike desktops. However, these lithium ion batteries may (and must) be charged eventually by plugging a power adaptor into an electrical socket, and during these periods the laptop is tethered exactly as if it were a desktop.
Aside from being equipped to store much of the same information and run many of the same programs as a desktop, laptops also operate the internet in the same manner. Dial-up modems, wired broadband solutions (ethernet), and wireless connectivity via included wireless cards are all available on laptops, depending on the model, with the dial-up modems gradually being phased out of most modern laptop designs, and instead added upon request by adding a surcharge to the overall total cost of the computer. Additionally, many laptops provide for Bluetooth connectivity.
Ports, Drives, and Updates
Ports and drives on laptops also mirror their desktop cousins. USB ports, Firewire ports, and audio in/out jacks are all hallmarks of laptops. Additionally, disk drives ranging from CD/DVD read/write drives to even the inclusion of high-definition Blu-Ray drives with some PC laptops are featured on laptop models. However, users should buy laptops with all the features they require in mind, as it is typically more difficult to update a laptop than a desktop, often due to the access to necessary features such as the hard drive or RAM, depending on the specific unit.