A door seal is a strip or material placed around the edges of a door to prevent air, water, and dust from entering a building. It helps improve energy efficiency by keeping heated or cooled air inside, reducing the need for heating or cooling systems to work harder. Door seals come in various materials, including rubber, foam, and vinyl, and can be found in both residential and commercial settings. Proper installation of a door seal can enhance comfort and protect against weather elements, making it an essential component for maintaining a well-insulated space.