This is about transparent, translucent, and opaque. Transparent: When the object lets most of the light pass through it without any interferance. Some examples are: Windows, Glass, Air, etc. Translucent: When an object only allows some light to pass through it because you can't see clearly through the materials. Some examples are: tinted sunglasses and smoke. Opaque: When an object doesn't allow any light to pass through out it, therefore it is either reflected or absorbed. Some examples are: wood/door and etc.