Which aspect of a wave can affect its speed in different media?

The speed of a wave is primarily determined by the medium through which it travels. Different media, such as air, water, or solid materials, have varying properties, such as density and elasticity, that impact how quickly a wave can move through them. For example, sound travels faster in water than in air because of the denser molecular structure of water, allowing for more efficient energy transfer. Similarly, light travels at different speeds in various materials based on their refractive indices. The medium's characteristics are essential because they influence the wave's speed, regardless of its frequency, wavelength, or energy.