Transparency
In optics, transparency is the property of allowing light to pass through something.
An object that is transparent can be seen through, i.e. what is on the other side of the object can be seen through it. The image you can see through a transparent object is similar to the image you can see without it. It may be changed if the transparent object behaves like a lens. This could change the size of the image or change its shape.
If some light can be seen through an object but some of the detail of the image is lost, it is a translucent material. The opposite of transparency is opacity.
Translucency
Examples of translucent materials are frosted glass, paper, and some types of amber.