VLAN
In plain terms
A logical network segment within a physical network.
Going deeper
A VLAN partitions one physical switch network into isolated logical networks, improving security and organization without separate hardware. Devices behave as if on separate LANs.
Under the hood
Tags (802.1Q) separate traffic; isolates broadcast domains and segments departments for security.
Examples
Network segmentation, isolating departments, security zones, switch configuration.
Think of it like...
Like dividing one open office into separate departments with virtual walls.