A WAN, or wide area network, is a computer network that spans a large geographical area, such as a city, state, or country, connecting several smaller local area networks (LANs). WANs are used to facilitate communication between computers separated by large distances and can support a variety of different data transmission methods, such as dedicated leased lines, broadband connections, and wireless transmission. WANs are typically used to connect businesses, government offices, and other large organizations.