The document discusses the history and types of tablet computers. It notes that tablet PCs, introduced in 2001, were laptop computers that could also be used as a tablet via a pen or finger. Modern tablets, popularized by the iPad in 2010, are based on mobile operating systems and use touchscreens rather than laptop components. Tablets now encompass a variety of devices that are differentiated based on their operating systems, such as iOS, Android, Windows, and Blackberry devices.