What does LAN stand for?
LAN stands for Local Area Network. A network covering a limited area such as an office or a home, usually segmented further with VLANs.
A LAN connects devices in one limited place, such as a home, an office floor or a building, on equipment the owner controls. Today that means Ethernet switches for wired devices and access points for wireless ones. Devices on the same LAN segment reach each other directly by MAC address, without a router. A router is needed only to leave the LAN. Larger LANs are divided into VLANs to keep groups of devices apart.
LAN in practice: an example
An office has forty PCs, three printers and a file server cabled to two switches, plus an access point for laptops. All of it is one LAN: a PC prints by sending frames straight to the printer through the switch. Only when someone opens a website does the traffic go to the router, which is the edge between the LAN and the provider's network.
What LAN is confused with
LAN vs WAN: what is the difference?
A LAN covers one site and belongs to the organization. A WAN links sites over long distances, usually on a carrier's circuits or the internet. On a home router, the LAN ports face your devices and the WAN port faces the provider. What WAN stands for
LAN vs VLAN: what is the difference?
A VLAN is a logical LAN created inside the switches. Devices in different VLANs are kept apart even on the same hardware and need a router to talk to each other. What VLAN stands for
Which exams cover LAN?
LAN is on the official CompTIA acronym list for three of the four exams covered here.
- Security+ SY0-801: on the acronym list, not tied to one objective.
- Network+ N10-009: 2.0 (Network Implementation).
- A+ 220-1201 and 220-1202: 220-1201 2.0 (Networking).
Each number is a CompTIA exam objective and the name in brackets is its domain. The exam puts the term in a scenario; it does not ask you to recite the expansion.
Check yourself: two practice questions
Written by CertSprint for this page. They are not taken from any exam.
1. Two PCs are connected to the same switch, in the same VLAN and subnet. Which device do they need in order to exchange files?
- Only the switch
- A router
- A modem
- A firewall
Show the answer
A. Only the switch. Devices in the same LAN segment communicate directly through the switch. A router is needed only to reach a different network.
2. On a small office router, which port is connected to the internet provider's equipment?
- The WAN port
- A LAN port
- The console port
- The USB port
Show the answer
A. The WAN port. The WAN port faces the provider and the LAN ports face the internal devices. The router routes between the two sides.
Sources: NIST glossary: local area network; IEEE 802.3: Standard for Ethernet. The acronym and its expansion come from CompTIA's official acronym lists, linked from each exam glossary above. The explanation, example and questions are CertSprint's own, checked against these sources on 12 November 2026.