Light can travel through various mediums, including vacuum and matter. In a vacuum, which is an empty space devoid of matter, light propagates in the form of electromagnetic waves. This is why light from distant stars and galaxies can reach us through the vastness of space.
In matter, such as air, water, or glass, light travels by interacting with the atoms or molecules present in the medium. When light enters a material medium, it can be absorbed, scattered, reflected, or refracted depending on the properties of the medium and the characteristics of the light.
For example, when light passes through a transparent material like glass, it can be refracted, which means it changes direction due to the change in speed as it moves from one medium to another. Similarly, when light encounters a rough surface or particles in the air, it can be scattered in different directions, leading to phenomena like diffusion or the scattering of sunlight in the atmosphere.
So, in summary, light can travel through a vacuum as electromagnetic waves and through matter by interacting with the atoms or molecules in the medium.