When buying a computer you will be faced with two options: a desktop PC or a laptop. Which one you end up buying will depend on your needs and, of course, your budget.
A desktop PC is one that will reside on a desk in your office or bedroom. It will come with separate parts — usually a tower, which contains the brains of the PC as well as the DVD drive. It will also come with a monitor, keyboard and mouse.
On the other hand, a laptop (or notebook) is an all-in-one device that is portable. It can be carried with you from room to room, home and work, or can be used while on the road (when travelling on a train, for example). Laptops have a battery that can last anywhere between one and a half hours to four hours, depending on the type of programs you use. Laptops have a built-in monitor, a built-in keyboard and a built-in mouse (called a touchpad or trackpad).
In the old days, if you wanted a fast computer, you had to buy a desktop PC. Currently the performance of a desktop PC and a laptop is similar and, in some cases, equal. The only area in which desktop PCs and laptops can differ greatly is in their ability to run games; although there are gaming laptops, they tend to be awkward to use and don't provide as much gaming performance as a desktop. If you want a computer to play the latest games, then you should definitely consider a desktop PC. If you want to buy a computer just so that you can use the Internet or type up documents and spreadsheets, then a laptop is a good choice.
The key specifications to look for when buying a desktop PC or a laptop are the CPU (central processing unit), RAM (random access memory), graphics adapter and hard drive. The CPU is the brains of the computer; the RAM is the space where all your programs will be loaded (the more RAM you have, the more programs you can load); the graphics adapter (also known as the graphics card or graphics controller) determines how well your computer will run games; and the hard drive determines how many programs, music files, documents, videos and e-mails you will be able to store on your computer.
Laptops will generally have slightly lower specifications than desktop PCs, although there's not much in it these days. A typical laptop might have a slower CPU speed and a smaller hard drive than a similarly priced desktop PC, and it will also have a less powerful graphics adapter. For the best performance, look for a laptop or desktop based on Intel's Second Generation Intel Core i3, Core i5 or Core i7 CPUs; or look for one that uses AMD's A4, A6 or A8 APUs (accelerated processing units, which is AMD's description of its CPUs).
Screen size and resolution
When buying a laptop, you will need to decide what size screen and screen resolution will be suitable for your needs. Screen size often determines the weight of the laptop (the bigger the screen, the heavier the laptop), while the resolution is the amount of information (in dots) that can fit onto the screen. A screen with a higher resolution allows you to see more of a Web page; it also allows you to more easily line up two documents side by side on the screen, which is aids multitasking.
A 15.6in (measured diagonally) screen means the notebook will be heavy (between 2.5kg and 3kg), and the most common resolution for a screen this size is 1366x768. If you want to watch Blu-ray movies or other high-definition content, then you should consider a laptop with a screen resolution of 1920x1080 (also called Full HD), although these are more expensive. Generally, if a laptop has a Blu-ray drive built-in, then it will come with a Full HD screen.
Laptops with 13in or 14in screens offer a good balance between size and portability and are commonly available in resolutions of either 1366x768 or 1600x900 (or 1440x900 if you go for a MacBook Air). If you want something even smaller and more portable, consider either a 10in or 11.6in netbook, which can weigh between 900g and 1.5kg. Ten inch netbooks often have a low resolution of 1024x600, which can be uncomfortable for Web browsing, while 11in netbooks have a more comfortable 1366x768 resolution.
A 19in LCD monitor used to be common for desktop PCs, but nowadays a 22in widescreen monitor offers the best screen size and value. It's worth spending a bit more on the monitor, and even upsizing to a 24in model if you can afford it, because the monitor is the one device that you will have to look at every time you use your PC.
Burning CDs and DVDs
Nearly all desktop PCs come with a DVD burner, and so do most 15.6in laptops. Many laptops smaller than 15.6in do not come with a built-in DVD burner, especially 10in and 11.6in netbooks, but some 13.3in and 14in laptops still have a built-in DVD burner. With a DVD burner you can burn CDs as well as DVDs. Blu-ray combo drives are also available, and these allow you to play Blu-ray movies, as well as burn CDs and DVDs. A Blu-ray writer is required if you want to burn your own high-definition video onto Blu-ray discs.
Do new laptops and desktop PCs come with software?
Nearly all laptops and desktop PCs come with a version of Microsoft Windows 7 preinstalled (and Mac OS X Lion for Macbooks). If they have a DVD burner, then should also come with software for burning CDs and DVDs and watching movies; the brand of laptop or desktop PC you buy will determine exactly what this software is. Some laptops and desktops may also include office application software, games, or educational software. Many models may also come with software to protect your computer from viruses, although this is often introductory and you need to buy a license to continue using the software after a period of time.
Why buy a laptop?
If you want a computer that you can use at home, as well as take to work, then you will need a laptop. Also, you may choose to buy a laptop if you want to have more freedom to roam when using your computer at home. A fully charged laptop can give you a few hours of use and will let you work from your living room, bedroom or even your backyard. On the other hand, a desktop PC will restrict you to working from the location where the PC is installed.
Why buy a desktop PC?
If you want a computer with the means to store a huge amount of music and video files or a computer that will let you comfortably play games, then a desktop PC is a good choice. A powerful desktop PC is generally less expensive than a powerful notebook with similar grunt, and a desktop PC also has an advantage in that it can be easily expanded if your needs change (you can add more storage, RAM or a better graphics card at a later date). A laptop cannot be expanded to the same extent that a desktop PC can, although you can change the hard drive and in most cases add more RAM.