There are three types of rice cookers that are available in the market. They differ in price and functionality. 1. Cook Only: This type of rice cooker only cooks and switches off once the rice is done. These are basic models of rice cookers. 2. Cook and Warm: These are rice cookers; they not only cook but also keep the food warm up to a certain time. The duration of this varies and incidentally, price varies too. 3. Electronic Cook and Keep Warm: These are high-end rice cookers that cook and can keep the food warm up to 12 hours.