What is 'unjust enrichment' in contract law?

Unjust enrichment in contract law refers to a situation where one party receives a benefit at the expense of another party under circumstances that the law considers unjust. The concept is rooted in the idea that it is unfair for someone to profit or gain from another's loss without providing appropriate compensation or payment. Therefore, when a party has gained a benefit without paying for it, they may be legally required to compensate the other party to prevent this inequity.

In the context of this question, gaining a benefit without paying for it directly captures the essence of unjust enrichment. The law seeks to prevent one party from being unjustly enriched at the expense of another, hence creating a legal obligation to make restitution for the value of the benefit received. This principle ensures that individuals or entities cannot retain benefits derived from a transaction that was not sufficiently compensated.