Simple definition
WireGuard on Linux creates encrypted Layer 3 VPN tunnels using kernel or userspace network interfaces.
Purpose and use
WireGuard on Linux provides a VPN interface whose peers are identified by public keys.
How does it work?
Encrypted communication uses UDP; allowed addresses participate in peer selection and received-source checks.
Example and verification
When expected traffic is absent, inspect public keys, routes, allowed addresses and handshake observations.
Points to watch
A recent handshake does not prove that DNS, routing and firewall policy permit application access. The UDP port is configurable.
In short
The tunnel supplies encrypted transport; useful connectivity requires separate verification.