A personal computer (PC), or simply computer, is a computer designed for personal use. It is typically used for tasks such as word processing, web browsing, email, file management, spreadsheets, and video calling. Personal computers are meant to be operated directly by an end user, rather than by a computer expert, administrator, company or technician. Unlike large, costly minicomputers and mainframes, time-sharing by many people at the same time is not used with personal computers. The term "home computer" has also been used, primarily in the late 1970s and 1980s. The advent of personal computers and the concurrent Digital Revolution have significantly affected the lives of people.