A VPN tunnel not only protects you from data being intercepted, but it also hides your IP address, which can otherwise be used to identify you when you are browsing the web. Instead of your real location, the sites you visit will only see the location of the VPN server you are connected to.
This is how VPN tunnels can help you both circumvent censorship imposed on your local network and censorship being imposed by the local network of the site you are visiting.