A deep fryer is a kitchen appliance designed for cooking food by submerging it in hot oil. This method allows for even cooking and creates a crispy texture on the outside while keeping the inside moist. Deep fryers come in various sizes, from small countertop models to larger commercial units, and can be used for frying a variety of foods, including potatoes, chicken, and doughnuts. Most deep fryers have adjustable temperature settings and safety features like automatic shut-off to prevent overheating. They often include a basket for easy food handling and a lid to minimize splatter. Proper maintenance and oil filtration are essential for optimal performance and food quality.