What is Hub?

Hub definition and meaning on Dictionary terms:
the central part of a wheel, as that part into which the spokes are inserted.
the central part or axle end from which blades or spokelike parts radiate on various devices, as on a fan or propeller.
a center around which other things revolve or from which they radiate; a focus of activity, authority, commerce, transportation, etc.: Chicago is a railroad hub.
the Hub, Boston, Mass. (used as a nickname).
the peg or hob used as a target in quoits and similar games.

any one of the holes in an electrical panel, into which connections may be plugged.
Coining. a design of hardened steel in relief, used as a punch in making a die.
Surveying. a stake bearing a tack used to mark a theodolite position.
Metalworking. a die forced into a metal blank.

verb (used with object), hubbed,
Metalworking. to stamp (a metal blank) with a hub.