Here's why:
* Opaque materials block all light. You can't see through them.
* Transparent materials let all light pass through, allowing you to see clearly through them.
* Translucent materials allow some light to pass through, but they scatter the light so you can't see clearly through them.
Examples of translucent materials include:
* Frosted glass
* Wax paper
* Thin paper
* Some types of plastic
* Stained glass