An endoscope is a medical instrument used to examine the interior of a body cavity or organ. It consists of a long, flexible tube equipped with a light and a camera at one end. This allows doctors to visualize areas such as the digestive tract, respiratory system, or other internal structures without making large incisions. Endoscopes can also be used for diagnostic purposes, such as taking biopsies or removing foreign objects. They are commonly used in procedures like gastroscopy for the stomach, colonoscopy for the colon, and bronchoscopy for the lungs, providing valuable information for patient care.