How much can pass at once. Used of channels and of minds — in both, exceeding it does not slow things, it drops them.

A degree on a scale, and the flatness of a plane. Both name a position measured against a fixed reference.

Varying one thing to carry another. Modulation is how a steady signal is made to hold meaning.

A deliberate sign sent to be read. What distinguishes signal from noise is that someone meant it.