A brick is a rectangular-shaped block of clay that is used in construction of different kinds of buildings. There are different kinds of bricks, and several factors that influence the engineer's choice of brick: the climate of the place where the building is located, the exact part of the building a brick is used for, the intended usage of the place, whether the brick is to be used for utility or for decoration, and more.
Facing bricks are those used to decorate the exterior of a building. They are the most visible bricks, so they are better in quality and more durable as well. Wirecut bricks are an example of facing bricks: These bricks are made with clay, textured, then cut by wire. The process of making wirebricks is automated, so these are less expensive to produce in large quantities. They are available in different colors and textures.
Building bricks are the most commonly used type of bricks. They are made of clay, and fired in kilns to bake them and make them hard and strong. They are used in construction of walls and other surfaces, and not for the exteriors --- so they do not come in different textures, or colors. They are hard and durable.
Glazed bricks have one side covered with glazed coating (generally ceramic). The glazed look comes from the fusion of different minerals and ingredients when the bricks are burnt or baked. The glazed surface makes these bricks best suited for hospitals, laboratories, dairies and other buildings where the maintenance of sanitary conditions is very essential.
There are several other types of bricks: handmade bricks, which are made by craftsmen pouring clay into singular moulds; engineering bricks, whose appearance is not as important as their performance, and are used to build retaining walls and sewers; re-pressed bricks, which are wirecut bricks pressed to create very solid bricks with exact sizes and textures; and concrete bricks, which are made of a mixture of cement and sand.