Legal Definition
A subcontract is a contract or agreement where one party (the subcontractor) agrees to perform a specific part of a larger project or service for another party (the prime contractor), typically involving the division of work within a larger scope.
Plain-English Translation
Imagine you are building a big Lego castle. Instead of building the whole thing yourself, you hire a smaller team (the subcontractor) to build just one specific tower or wall. The main person who hired you is the 'prime contractor'.