One question I frequently get about @cosmos #IBC interoperability is about the core distinction between a hub and a zone: None. Here's why and what it means in terms of a chain's core value proposition (thread)

The core IBC protocol, i.e the one that handles transport, authentication, and ordering (TAO) of data packets, has no context about the overall network topology, i.e connections between chains.

The core protocol only defines the set of required functions and properties for chains that communicate on the #interchain. These are defined in the form of Interchain Standards (ICS): https://github.com/cosmos/ics 

IBC doesn't prevent any sovereign chain from connecting to all other chains directly (without hops). But then, what distinguishes a hub from a zone if not the number of connections? Does it mean that the cosmos whitepaper was wrong? Not quite.

A Hub in the @cosmos network, defined initially as a central chain to which the other chains/zones are connected, is **entirely** labeled as such by social consensus around its utility and value proposition

A good analogy from @sunnya97: think of the cosmos network as the network of commercial flying routes/paths in the globe. An airport would correspond to any #cosmos chain and planes are IBC packets being transferred around

There's nothing preventing a reasonably sized airplane with enough gas to fly from one airport to another. Nevertheless, some airports emerge naturally as hubs, whether because they are located strategically, in a large city or they provide better infrastructure and services

This year, the Cosmos Hub's #ATOM2021 initiative will introduce numerous features, services, and infrastructure utilities to position itself and the $ATOM at the center of the Interchain. https://twitter.com/jack_zampolin/status/1350130109634682880