A reconstructive operation is surgery that rebuilds a part of the body so it has a more natural shape and can work again — after a bad injury, a burn, cancer surgery, or a previous operation that left something wrong. Reconstructive surgery is about putting function and form back. People often set it next to cosmetic surgery, which is mainly about appearance; though actually, in a real hospital the two can overlap, and a reconstructive operation may also change how someone looks. The adjective also appears outside medicine: a reconstructive account of history tries to build the past again from pieces. For learners, the medical sense is the one that matters first.