Today, simple computers may be made small enough to fit into a wristwatch and be powered from a watch battery. Personal computers, in various forms, are icons of the Information Age and are what most people think of as “a computer”; however, the most common form of computer in use today is the embedded computer. Embedded computers are small, simple devices that are used to control other devices â€” for example; they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, and children’s toys. Today a PC may be a desktop computer, a laptop computer or a tablet computer. The most common operating systems are Microsoft Windows, Mac OS X and Linux. Software applications for personal computers include word processing, spreadsheets, databases, games, and a myriad of personal productivity and special-purpose software. Modern personal computers often have high-speed or dial-up connections to the Internet, allowing access to the World Wide Web and a wide range of other resources. Because of the use of desktop pc in every sphere of life, they are in great demand and therefore cheap desktop PCs are available in the market. Now dayâ€™s laptops are more commonly used because of its portability. A laptop computer, also called a notebook computer or sometimes a notebook, is a small personal computer designed for mobility. Usually all of the interface hardware needed to operate the laptop, such as parallel and serial ports, graphics card, sound channel, etc., are built in to a single unit. Most laptops contain batteries to facilitate operation without a readily available electrical outlet. In the interest of saving power, weight and space, they usually share RAM with the video channel, slowing their performance compared to an equivalent desktop pc.Now days cheap laptops are available in the market. A subtype of notebooks, called subnotebooks, are computers with most of the features of a standard laptop computer but smaller. They are larger than hand-held computers, and usually run full versions of desktop/laptop operating systems. Ultra-Mobile PCs (UMPC) are usually considered subnotebooks, or more specifically, subnotebook Tablet PCs. In todayâ€™s world of technology gaming pc or gaming computers are widely available in the market, these are the computers specifically built to play PC games at a higher frame rate, higher resolution and higher graphical settings than domestic PCs.Due to the tough competition in the market now days cheap gaming PCs are also available in the market.