I need help understanding how to answer the physics question below please; I think I get it, but I'm still a little confused. The subject is thermodynamics, specifically the first law of thermodynamics. Thank you.

A refrigerator operates by compressing and expanding gases to create temperature differences. To cool the inside of a refrigerator, gas must expand. Does this expansion represent a gain of work energy by the gas or a loss of work energy by the gas? Explain your reasoning. The space behind a refrigerator is usually hot. This is because the gases that expanded into the refrigerator are being re-compressed so that they can use again. Does this compression represent a gain of work energy by the gas or a loss of work energy by the gas? Explain your reasoning