What are untagged and tagged VLAN

[guest]

If you want multiple vlans to pass via a switch interface, those vlans need to be tagged by configuring a trunk port on a cisco switch. Tagged vlan = we tagged more than one vlan in the trunk port or Trunk Port = Tagged (IEEE 802.1q tagging vlans and sending inside the trunk)

Access ports are typically untagged, meaning only one vlan passes via the interface. Untagged vlan = we just configured the switchport as access port or Access Port = Untagged.

Note: All vlans, except the native VLAN when using 802.1Q, are tagged when trunking.