“Priority : The first three bits of the TCI define user priority, giving eight (2^3 ) priority levels. The deafult value os 0, indicating normal treatment. IEEE 802.1P defines the operation for these 3 user priority bits (defined in the IEEE 802.1D standard).
The QoS VLAN Priority lets you assign a priority to outbound packets containing the specified VLAN-ID (VID). Packets containing the specified VID are marked with the priority level configured for the VID classifier. This 802.1 priority determines the outbound port queue to which the packet is sent. If the packet leaves the switch in a tagged VLAN, it carries the 802.1p priority with it to the next downstream device.