Transparent materials allow light to pass through them easily, with little or no scattering or absorption. Examples of transparent materials include glass, water, and clear plastic.
Opaque materials do not allow light to pass through them. They either reflect or absorb all the light that hits them. Examples of opaque materials include wood, metal, and paper.
The transparency or opacity of a material is determined by its internal structure and composition. In general, materials with regularly arranged atoms or molecules tend to be transparent, while materials with irregular structures tend to be opaque.
