To put it very simply, a microwave oven is a device in which food is cooked by the heat produced by the absorption of microwave energy by water molecules in the food. Microwave ovens operate by agitating the water molecules in the food, causing them to vibrate, which produces heat. The microwaves enter through openings in the top of the cooking cavity, where a stirrer scatters them evenly throughout the oven. They are unable to enter a metal container to heat food (causing sparks), but they can pass through non-metal containers.
There are many microwave ovens available nowadays. All fall into three main categories. The countertop microwaves are the most popular and take up less space. Some have a rack or shelf, thus offering two cooking positions and are more complicated to use. Usually the food on the shelf gets more of the microwave energy than that on the base so you have to select foods that will together satisfactorily. Remember, timings will be different if cooking more than one item at a time. Double oven microwaves are available as either freestanding cookers with hob or as a double oven unit. (You can start cooking a joint of meat in the microwave and then brown it in a conventional oven.)
Microwave ovens offer impressive speed and convenience. Today's models have child lockouts with keypad releases. Other improvements include automatic defrosting and a range of programmed power and time settings for the most popular microwave foods, such as pizzas. Some models even organize foods by ethnic category, such as Chinese and Italian, and cook accordingly. These features apart, the real differences are in power, capacity, cooking sensors, and convection-heat options. Power is measured in watts, starting at 600 and ending near 1000. More power means shorter cooking times. Power is usually coupled with size. With more power and you'll get a larger cabinet, plus a carousel, which eliminates the need to stop and stir. Cabinet sizes start at around 0.5 cubic feet and end near 1.3 cubic feet. Many models have built-in sensors that prevent food from overcooking by monitoring moisture levels. When a sensor determines that a meal has shed most of its water through cooking, it signals that the meal is ready. Some top-end models add convection heat so foods can be browned without moving to a conventional oven before serving
Now it is possible to cook delicious Indian food in microwaves. Unlike the conventional indian food, microwave cooked food is low calorie. The process of cooking the food is clean and efficient. One can serve the food in the same vessel one cooked food in. So there is less washing involved. Happy Cooking !!!