As the work progresses, the bricks are laid in rows called courses. The manner in which the bricks overlap as they are laid up is called the bond. The most common type of brickwork seen these days is the monotonous stretcher bond, showing only the long side-surface of the brick. A brick laid with its side exposed like this is called a stretcher, as opposed to a header, where only the end of the brick can be seen in the brickwork.
Because only the outside of finished brickwork is visible, cheaper grades of brick are commonly used for the hidden parts of a wall. In an old red-brick house, behind the front of red, the rest of the walls are often made of softer yellow bricks. So with certain types of bond (e.g. garden wall bond) it is possible to use a higher ratio of cheaper bricks to more expensive bricks, making for a cheaper wall of the same dimensions. On the same house, sometimes a more economical "garden wall" bond has been used at the side and rear compared to the front.
The thickness of brickwork is measured in units of brick. If you put some bricks down end-to-end with the long side facing you (stretchers) and then another row on top, the wall thickness is half a brick.
There are rules of bonding, which have some exceptions. These specify the overlap between courses that is visible outside the wall, and also the overlap which must be made within the wall, for walls which are more than half a brick thick.
Brickwork, like unreinforced concrete, has little tensile strength, and works by everything being kept in compression.
Brickwork arches can span great distances, and carry considerable loads.