What is VLan ?

VLan (Virtual Local Area Network) :

A virtual local area network is a logical group of work stations and

 network devices that appear to be on the same LAN despite their 

geographical distribution. A VLan allows a network of computer and 

users to communicate in a simulated environment as if they exist in

 a single LAN and are sharing a single broad cast and multicast 

domain. 

Vlan are used for security and scalability.

A VLan allows several networks to work virtually as a Lan. One of the benefit of vlan is it removes latency in the network. Traffic issue could easily be controlled by vlan. 

Advantages of Vlan:  

   

    Allow administrator to secure network communication.

    It provide flexibility 

    It does decrease latency and traffic load on the 

       network and its devices  

Disadvantages :    

    Virus issue : An infected system may spread the virus in

        the entire logical network      

   

 Equipment Limitation could be occure in a large network.Because

         it might need additional routers.

       More effective at controlling latency than a wan but less 

           efficient than a Lan.