OnionCat creates a transparent IP layer on top of Tor's hidden services. It transmits any kind of IP-based data transparently through the Tor network on a location hidden basis. You can think of it as a point-to-multipoint VPN between hidden services. Its architecture guarantees that the real IP of users cannot be revealed in any way. Tor also provides so-called Hidden Services. Those are services which are hidden within the Tor network. This means that not only the user stays anonymous but also the service (destination).