Port VLAN and native VLAN are synonymous terms. The IEEE 802.1Q standard and most vendor switches use the term port VLAN, but Cisco switches use the term native VLAN.

Every port has a port VLAN or a native VLAN. Unless otherwise configured, VLAN 1 is the default VLAN. It can be configured on a per-port basis or over a range of ports.

All untagged Ethernet frames (with no 802.1Q tag, for example, from a personal computer) are forwarded on the port VLAN or the native VLAN. This is true even if the Ethernet switch port is configured as an 802.1Q trunk or otherwise configured for multiple VLANs.