A door is a movable barrier that allows entry and exit to a space, such as a room or building. Typically made of materials like wood, metal, or glass, doors can swing open or closed on hinges. They serve various functions, including providing privacy, security, and protection from the elements. Doors come in many styles and designs, including sliding doors, French doors, and bi-fold doors. They can be equipped with locks and handles for ease of use and safety. In addition to their practical purposes, doors can also enhance the aesthetic appeal of a space, contributing to its overall design.