Wikimedia
Wikipedia: Local Area Network (Lan)
Wikipedia provides an encyclopedia definition of a local area network, or LAN, including many hyperlinked terms.
Tech Target
Search Networking: Local Area Network
A simple definition of the term, "Local Area Network," or "LAN" including hyperlinked terms.
Other
Connected: La Ns and Wa Ns
The definitions and comparisons between Local Area Networks (LANs), and Wide Area Networks (WANs).
Wikimedia
Wikipedia: Computer Network
This site contains a Wikipedia description of computer networks.
Other
Webopedia.com: Local Area Networks
This site from Webopedia.com provides definition and uses of Local Area Networks. Includes LAN characteristics with linked definitions. Has many links to related sites.
Other
Tech Soup: Networking 101: Concepts and Definitions
Starts with a simple definition of a network and then explores the components of a network, how a network works, types of networks, communication protocol, and hardware.