* Solids: Waves can travel through solids as vibrations. Think of a sound wave traveling through a metal bar.

* Liquids: Waves travel through liquids as compressions and rarefactions. Sound waves travel through water, creating pressure changes.

* Gases: Sound waves travel through gases (like air) by compressing and expanding the molecules.

In short, any medium with particles that can interact and transmit energy can support wave propagation.