A domestic deep fryer is used to cook foods by fully submerging them in hot oil (typically 350-375°F or 175-190°C), creating a crispy exterior while keeping the interior moist. Common uses include making French fries, fried chicken, onion rings, doughnuts, and fried seafood like calamari and fish, as well as other items like cheese sticks and tempura. Deep frying is an indulgent cooking method that requires careful temperature control, safety measures, and a proper cleanup routine.