VLAN’s allow you to breakup the switch into separate virtual local area networks. VLAN’s can help us save resources by:
Limiting broadcasts… particularly the broadcasts to hosts that DO NOT need them.
You do this by increasing the number of broadcast domains.
Prevent broadcast storms that render a switch virtually useless
Help you logically segment the LAN to increase security. ie.
Separating departments on a LAN so “accounting users” will not talk with “building maintenance users”.