A Virtual local area network (VLAN) is a logical group of workstations, servers, and network devices that allows a network of computers and users to communicate in a simulated environment as if they exist in a single LAN and are sharing a single broadcast and multicast domain.

Explain how does a VLAN saves a company time and money. Discuss how VLAN provides extra security and mitigate traffic for a network. You may include relevant references and citations.