Probably you’ve seen different types of bricks already and you are not sure why is that so. In the different parts of the world are used different ones. For the different type of constructions also are used different bricks too. Based on the way they were made we can divide them on unburnt or sun-dried bricks (dried with the help of or the sun heat after the process of moulding) and burnt bricks (exposed on some kind of heat and burning the brick-mould in the kiln in the factory).
Unburnt bricks are used in the construction of temporary and cheap structures on the places that are NOT exposed to heavy rains. Burnt bricks are commonly used material for construction and they are classified into four categories further.

Source.

...