NotVPN refers to the practice of bypassing the filtering mechanism of a VPN service to access content or websites that would otherwise be blocked. While VPNs are designed to filter traffic from certain regions, they do so by either filtering the traffic or redirecting it. Therefore, "not VPN" means not using a VPN to block traffic, even though the user is still blocked by their own network. This context is about bypassing the filtering to access outside content.
