As the question is general so as per my knowledge i am answering it generally. What i know if something is specific i request you to explain it.
Both are electronic fundamentals to select/choose/increase/decrease the voltages/frequencies.
Offset means a small deviation or bias in a voltage or current. It is a numerical value stored in the controller to control the components of machine. It is used to adjust for variations.
Hysteresis is the delay between action and reaction of a measuring instrument. Hysteresis is the amount of error that results when this action occurs.