Cosmos ecosystem has two classes of blockchains: Hubs and Zones. Zones are regular heterogenous blockchains and Hubs are blockchains specifically designed to connect Zones together. When a Zone creates an IBC connection with a Hub, it can automatically access (i.e. send to and receive from) every other Zone that is connected to it. As a result, each Zone only needs to establish a limited number of connections with a restricted set of Hubs. Hubs also prevent double spending among Zones. This means that when a Zone receives a token from a Hub, it only needs to trust the origin Zone of this token and the Hub.
