PVID = Port Vlan ID
PVID (Port VLAN ID) is a default VLAN id assigned to frames coming to the port
Example 1.
interface fa0/1 switchport mode access switchport access vlan 10 switchport voice vlan 20 switchport trunk native vlan 30
Here PVID is 10, as untagged frames will get into VLAN 10.
Example 2
interface fa0/2 switchport mode trunk switchport access vlan 10 switchport voice vlan 20 switchport trunk native vlan 30
Here PVID is 30, as untagged frames will get into VLAN 30.