"The iPad is a tablet computer designed and developed by Apple. It is particularly marketed as a platform for audio and visual media such as books, periodicals, movies, music, and games, as well as web content. At about 700 grams, its size and weight are between those of most contemporary smartphones and laptop computers. Apple released the iPad in April 2010, and sold 3 million of the devices in 80 days.
The iPad runs the same operating system as the earlier iPod Touch and iPhone, albeit a slightly older version. (The versions are to be synced in September 2010.) It can run its own applications as well as ones developed for the iPhone. Without modification, it will only run programs approved by Apple and distributed via its online store.
Like iPhone and iPod Touch, the iPad is controlled by a multitouch display sensitive to up to eleven fingers -- a break from most previous tablet computers, which used a pressure-triggered stylus. The iPad uses Wi-Fi or a 3G mobile data connection to browse the Internet, load and stream media, and install software. The device is managed and synced by iTunes on a personal computer via USB cable.
Source: Wikipedia, "iPad", available under the CC-BY-SA License