GVRP stands for GARP VLAN Registration Protocol. It's a Layer 2 network protocol, for automatic configuration of the switches in a VLAN network.

Each VLAN switch is configured with the VLANs it is part of. GVRP will spread this information and configure the needed VLANs.

So to add a switch to a VLAN, only 1 switch needs to be reconfigured. This is not the case within a standard VLAN, where all switches might need reconfiguration.