A biopsy is a medical procedure in which a small sample of tissue is removed from the body for examination under a microscope. It is commonly used to diagnose diseases, such as cancer, by analyzing the tissue for abnormalities. Biopsies can be performed on various parts of the body, and the procedure may involve using needles, forceps, or surgical instruments, depending on the location and type of tissue being sampled. The results help determine the nature and extent of a condition, guiding treatment decisions.