How is electro, agnitic energy from the microwave transformed into heat energy?

Electromagnetic energy from the microwave is transformed into heat energy by the magnetron that it has inside. The magnetron is the part of the microwave that generates microwave that would interact with the molecules of what is put inside the microwave, which is usually food. The interaction between the microwave produced by the magnetron, which is produced at the right frequency, and the molecules of the food makes the molecules of the food agitate and in turn, creates friction which then heats up the food.