The difference between Onpass and Relay

Onpass as a verb (transitive):

To pass along or hand over.

Relay as a noun (hunting, now, _, rare):

A new set of hounds.

Relay as a noun (now, _, chiefly, historical):

A new set of horses kept along a specific route so that they can replace animals that are tired.

Relay as a noun (by extension):

A new set of anything.

Relay as a noun:

A series of vehicles travelling in sequence.

Relay as a noun (athletics):

A track and field discipline where runners take turns in carrying a baton from start to finish. Most common events are 4x100 meter and 4x400 meter competitions.

Relay as a noun (electronics):

An electrical actuator that allows a relatively small electrical voltage or current to control a larger voltage or current.

Relay as a verb (obsolete, intransitive, hunting):

To release a new set of hounds.

Relay as a verb (transitive, now, _, rare):

To place (people or horses) in relays, such that one can take over from another.

Relay as a verb (intransitive, now, _, rare):

To take on a new relay of horses; to change horses.

Relay as a verb (transitive):

To pass on or transfer (information).

Relay as a verb: