Hi,

My understanding is that they are different. You use the pvlanid when you are going to configure a switch port where you need to specify the Vlan ID, for example:

switchport access vlan "vlanid" or

spanning-tree vlan "vlanid"

Tagging is a mechanism used by the trunking protocol to identify Vlans. It add a tag to every encapsulated frame that contains the Vlan number.

Let me know if it helps.