A defroster is a device used in vehicles and buildings to remove frost, ice, or condensation from windows and surfaces. In cars, it typically blows warm air onto the windshield and side windows to improve visibility during cold weather. This feature is essential for safe driving, as it helps prevent accidents caused by obstructed views. In homes, defrosters can be found in appliances like refrigerators and freezers, where they help maintain optimal temperatures by preventing ice buildup. These systems often use heating elements or fans to melt ice, ensuring efficient operation and preserving food quality.