Here's why:

* Wavelength and frequency are inversely proportional. This means that as one increases, the other decreases.

* The speed of light (c) is constant. The relationship between wavelength (λ), frequency (f), and the speed of light (c) is given by:

c = λf

* If the wavelength is short, the frequency must be high to maintain a constant speed of light.

Think of it like this:

Imagine a wave on a string. If you make the waves closer together (short wavelength), you have to move your hand back and forth faster (high frequency) to keep the waves moving at the same speed.

Examples:

* Gamma rays have the shortest wavelengths and highest frequencies in the electromagnetic spectrum.

* Radio waves have the longest wavelengths and lowest frequencies.