Cellphones:

* Radio waves: Cellphones use radio waves to communicate with cell towers. These waves are a type of electromagnetic radiation with a longer wavelength and lower frequency than visible light.

Ovens:

* Microwaves: Microwave ovens use microwaves to heat food. Microwaves are also a type of electromagnetic radiation, but with a shorter wavelength and higher frequency than radio waves.

Key differences:

* Frequency: Microwaves have a higher frequency than radio waves.

* Energy: Microwaves have more energy than radio waves, which is why they can heat food.

* Penetration: Radio waves can penetrate walls and other objects, while microwaves are absorbed by water molecules in food.

It's important to note that both radio waves and microwaves are forms of electromagnetic radiation, but they have different properties that make them suitable for different applications.