Stands for "Local Area Network," and is pronounced like "land" without the "d". (Computer people will think you're weird if you pronouce it "L-A-N"). A LAN is a computer network limited to a small area such as an office building, university, or even a residential home. Most mid to large-sized businesses today use LANs, which makes it easy for employees to share information. Currently, the most common type of LANs are Ethernet-based and use software from Novell or Oracle. However, with the emergence of wireless networking, wireless LANs have become a popular alternative.