VLAN creates broadcast domain

doman= a group of network

First of all , VLAN creates BROADCAST DOMAIN , VLAN never create collision domain.

What make people confuse with broadcast domain and collision domain ?

Most of the time , we will think that broadcast create collision , so , broadcast domain sound like collision domain .

It is true that broadcast involve collision. But in Network world , the definition of the broadcast domain and collision domain are difference .

Basically , in networking , collision domain is belong to network with hub connection . Hub , creates collision .

In the networking world , we say switch reduce collision ( it is true ) , but Hub cannot reduce collision .

So, collision domain is related to Hub networking only , and collision domain is nothing to do with switch networking , because switch stop collision ( in fact , switch reduce collision )

Switch broadcast ( it is true ) , so , switch create broadcast domain .

So when switch is present in the network “A” , then the network “A” is in broadcast domain . Switch creates broadcast domain.

But , once switch is present in network “A” , the collision domain will have to be eliminated from this network “A” . Switch stop/reduce collision.

Router, stops broadcast + collision

Switch , stops collision . ( in fact is reduce not totally stop collision )

VLAN is switch based , so VLAN creates broadcast domain and not collision domain .