A microwave oven heats food using a process called "microwave heating." Inside the oven, there is a device called a magnetron that generates microwaves. These microwaves are a type of electromagnetic radiation with a specific frequency, usually around 2.45 gigahertz.
When the microwave is turned on, the magnetron produces these microwaves, which then travel into the oven's cavity. The microwaves reflect off the metal walls of the oven and pass through the food.
Food contains water, fats, sugars, and certain other molecules that can absorb microwave energy. As the microwaves pass through the food, they excite these molecules, causing them to vibrate rapidly. This vibration generates heat, which then spreads throughout the food.
Unlike conventional ovens that heat food by heating the surrounding air, microwave ovens directly heat the food from within. This allows for faster and more efficient heating, as the microwaves penetrate the food and heat it from the inside out.
It's important to note that microwave ovens only heat the food and not the container it is in. This is because most microwave-safe containers are designed to be transparent or reflective to microwaves, allowing the waves to pass through them without being absorbed or causing damage.