A tablet personal computer (PC) is a cross between a laptop or notebook computer and a personal digital assistant (PDA). It's essentially a flat-panel portable computer. The user either taps on the screen with his or her finger or with a stylus, or he or she uses a stylus to write on the screen. A tablet PC can wirelessly connect to the Internet and other computers. The term "tablet PC" originally referred to a specific brand or tablets that were compatible with certain operating systems, but any tablet-sized computer has come to be referred to in some instances as a tablet PC.
The main feature of a tablet computer is portability. These devices typically are about the size of a thin book — roughly 7 to 8 inches (17.8 to 20.3 cm) wide by 9 to 10 inches (22.9 to 25.4 cm) tall and about 0.5 inches (1.27 cm) thick or less, although some might be slightly larger or smaller. They usually weigh less than 2 or 3 pounds (0.9 or 1.36 kg). Their size makes them convenient for businesspeople, students and just about anyone else to take with them in whatever they use to carry their belongings, such as a briefcase, backpack or purse.
Some tablet PCs come with detachable keyboards that allow them to function like laptop computers. Others have separate keyboards that are accessory items, rather than part of the normal device. There are even models that have the clamshell design of a typical laptop, with a literal twist — the screen can rotate 180 degrees and can be closed with the screen-side up so that the tablet PC can continue to be used without the keyboard.
A tablet PC can be used for many purposes, including business, education and entertainment. Many of these devices use the same operating systems as desktop or laptop computers and can be connected to them for things such as managing content and transferring files. Some tablet computers allow their users to download special applications that work only on specific brands or types of devices. Most are able to connect to the Internet using wireless technology, and some are able to do so through cellular phone communication technology, thereby giving their users Internet access in a much wider area.