The term "shift" has multiple meanings, depending on its context.
1) In a general sense, it refers to any change or movement from one position, state, or activity to another. For example, "I need to shift my car into drive."
2) It can also refer to the time of day when work is done, such as in the phrase "working the night shift" which means working during the evening hours.
3) In a more specific sense, it refers to a change in gears while driving a manual transmission vehicle. For example, if you say "I need to shift my car into park," that means putting your car's gear into neutral so that it can come to a complete stop.