Man-made describes something created by humans rather than occurring naturally. A wooden table is man-made because people cut down a tree, shaped the wood, and assembled the pieces. A living tree growing in a forest is natural, not man-made.

The distinction matters in many contexts. Scientists study both natural lakes formed by glaciers and man-made reservoirs built by constructing dams. Environmental rules often treat man-made and natural materials differently: a man-made plastic bottle breaks down much more slowly than a natural banana peel.

The term can describe physical objects like buildings, roads, and computers, but it can also refer to created systems and concepts. Laws are man-made: people wrote them and can change them. Mathematical proofs are man-made discoveries about naturally existing mathematical relationships.

Sometimes people use artificial or synthetic to mean nearly the same thing, though these words often carry different connotations. Man-made emphasizes human creation without necessarily suggesting something is inferior to the natural version. A man-made satellite orbiting Earth serves purposes no natural object could fulfill.