VLAN ( Virtual Local Area Network) is a concept of creating distinct broadcast domains. It is a network which aims at partitioning the physical network. VLAN comprises all the attributes same as of a LAN (Local Area Network).
David Davis (2009) cites that "It is important to point out that you don't have to configure a VLAN until your network gets so large and has so much traffic that you need one. Many times, people are simply using VLAN's because the network they are working on was already using them". It is a broadcast domain which is developed by a switch as generally a router is used.