Hub is a lightweight piece of technology that connects data and applications securely in real-time. It allows users and organizations to connect different connector and client applications through a central Hub Server. The Hub Server can run on a user machine for local communications or on a network server, in a public cloud or in a hybrid environment with on-prem and cloud components for remote connections and multi-user access. This allows programmatic access to applications and remote execution of scripts.
Below image shows example of Hub connector applications and Hub client applications.