VLAN Configuration Step by step in Cisco packet tracer
“A virtual LAN (VLAN) is a group of networking devices in the same broadcast domain”
It is the concept of VLAN that most of the books are using but it doesn’t help us understand the benefits of VLANs. If you ask “What is a LAN?” you will receive the same answer: it is also a group of networking devices in the same broadcast domain!
To make it clearer, I expanded the above statement into a bit longer statement :)
“A virtual LAN (VLAN) is a group of networking devices in the same broadcast domain, logically”
It means that the devices in the same VLAN may be widely separated in the network, both by geography and location. VLANs logically segment the network into different broadcast domains so that packets are only switched between ports that are designated for the same VLAN.