What is the difference between VVID and PVID as regards IP telephony?

PVID = PORT VLAN ID in trunk port its send data with VLAN TAG, PVID can carry voice packet too but there is diffrent between VVID PVID . Cisco develop the name  VOICE VLAN thoug the concept was already there .  And any IP telephony office desk environment pleple need PC & IP Phone .Both need diffrent connection otherwise voice data will be go along  with   PC data if in same link . so Cisco use single port configure as access port (PVID) for PC which is totaly untaged and VOICE VLAN which is tag &  801.p QoS marked so its should not fallen behind any data packet.

Hope its useful for you 

PVID is the regular data vlan or native vlan used to traffic the voice packets

VVID is a unique vlan created to carry the voice packets