A glass block is a building material, it is sometimes called a glass brick and it can be used like a brick. Glass blocks however are very different from bricks. First they are made of glass and as such let light filter through. Unlike bricks they are a very good insulating material. Because a glass block is made of two glass sections joined together by a heat process a good mass of air is trapped inside the block. This air works in the same manner that a double insulated glass pane works in regular windows, only more so since the thickness is much greater. A typical glass block is between 5 to 8 inches thick.
Just as bricks have been used in the past as decorative elements as well as building materials, so can glass blocks be used. But we should dismiss the totally utilitarian role they play in construction. One area where they are more utilitarian than esthetic is for basement windows. Basement windows are notorious for being points of entry for burglars in homes. They are easily broken and often not very visible. Replacing a basement window with glass blocks windows is an easy project that most handy men can do. Because the window does not open and not easily broken, the entry point is eliminated. Furthermore it can provide a more pleasant diffused light into an otherwise somber basement.
Glass blocks are used for a wide variety of building projects. They can provide a decorative partition between two rooms or in a very large room separate two distinct areas. They can be used in kitchens, they could become the support for a breakfast bar. In a bath glass blocks can provide a shower enclosure that is easy to maintain. In a dark hallway you can add some natural light by replacing a part of wall with a section of glass blocks.
The ideas are endless, because they are easy to use, beautiful and versatile you should look at glass blocks if you have any remodeling projects.