In a VLAN stations are separated into groups by Switch.
Groups of users need to be on the same broadcast domain because they are running the same applications. An example would be a company that has VoIP phones. The users using the phone could be on a different VLAN, not with the regular users. Or, just to make a single switch into multiple virtual switches.
Network architects set up VLANs to provide network segmentation. ... VLANs can help manage broadcast traffic by forming multiple broadcast domains. Breaking up a large network into smaller independent segments reduces the amount of broadcast traffic each network device and network segment has to bear.
Advantages of VLANs. VLANs provide a number of advantages, such as ease of administration, confinement of broadcast domains, reduced broadcast traffic, and enforcement of security policies. VLANs provide the following advantages: VLANs enable logical grouping of end-stations that are physically dispersed on a network.
VTP version 1 and version 2 support only normal-range VLANs (VLAN IDs 1 to 1005). In these versions, the switch must be in VTP transparent mode when you create VLAN IDs from 1006 to 4094. VTP version 3 supports the entire VLAN range (VLANs 1 to 4094).