A VLAN is a group of switch ports administratively configured to share the same broadcast domain.
Private VLANs (PVLANs) are used mainly by service providers. The main purpose of Private VLAN (PVLAN) is to provide the ability to isolate hosts at Layer 2 instead of Layer 3.By using PVLAN we are splitting that domain into some smaller broadcast domains. In other words we may summarize Private Vlan as “Vlans in Vlan“.
Below tables enlists the difference between both –