Here's why:

* Wave speed is determined by the properties of the medium. This includes factors like density, elasticity, and temperature.

* Frequency is related to the source of the wave. A higher frequency wave means the source is vibrating faster.

Think of it like this: Imagine a rope tied to a wall. If you shake the rope slowly, you create a wave with a low frequency and long wavelength. If you shake it faster, the frequency increases, and the wavelength shortens. However, the speed at which the wave travels along the rope remains the same, regardless of the frequency.

Important Note: This applies to waves within a specific medium. When a wave moves from one medium to another (like light going from air to water), its speed changes because the properties of the medium change.