They’re similar but mainly Tailscale arranges WireGuard tunnels between peers. There are tons of useful features around that functionality like being able to route specific traffic through specific hosts (“nodes” using “app connectors”); it’s even better at finding a way out of hostile networks using relays.

Just as an example I typically use my VPS as an “exit node” so that all my traffic routes through it (which does a ton of tunnel hopping through commercial VPNs) while my wife isn’t into that at all, but both of us have Tailscale on our devices so when either of us accesses Home Assistant it’s routed directly to the host hosting it.