Fidelity

Fidelity is a notion, that at its most abstract level implies a truthful connection to a source. It's original meaning dealt with loyalty to a lord or a king, which was derived from one's responsibility or duty.

In recent times, fidelity has come to denote how accurate a copy is to its source. For example a worn gramophone record will have a lower fidelity than one in good condition, and a recording made by a low budget record company in the early 20th century is likely to have significantly less audio fidelity than a good modern recording.

Fidelity in a human relationship (mainly marriage) is generally held to mean monogamy and a lack of adultery.