What paid off and in ordinary mean

What did it mean to pay off a Royal Navy ship and place her in ordinary?

Paying off removed the ship from commission and dispersed most of the crew; in ordinary she remained afloat in reserve under a minimal caretaker establishment until recommissioning or deeper dockyard work.

The phrase paid off refers literally to paying and disbanding the ship's active crew as the vessel leaves commission. A ship in ordinary retained only enough people, often centered on maintenance specialists such as a carpenter, to keep her safe and afloat. Transfer into a dockyard for extensive work represented a deeper material state than ordinary reserve.