LAN

A LAN (Local Area Network) is a network connecting devices within a defined physical area — a single office, building, or campus. It's the "inside" of your network, as opposed to the internet-facing WAN.

Your LAN is everything inside your network perimeter: workstations, servers, printers, phones, cameras, and the switches and access points connecting them. Traffic within the LAN typically moves at 1Gbps to 10Gbps on wired connections and doesn't touch your internet circuit.

Modern LANs are built on Ethernet (IEEE 802.3) for wired connections and Wi-Fi (IEEE 802.11) for wireless. They're almost universally segmented into VLANs — logical subdivisions that isolate different types of traffic on the same physical infrastructure.

The LAN is where you have full control: you define the IP addressing, set security policies, control routing, and choose what can reach what. This is distinct from the WAN, where traffic is handled by your ISP and the public internet.

For small organizations, the "LAN" often means a single flat network behind a firewall/router. For larger or more security-conscious environments, the LAN is segmented: a separate VLAN for workstations, servers, management, IoT, and guests — each with appropriate firewall rules between them.