A course is a continuous horizontal layer of similarly-sized building material one unit high, usually in a wall. The term is almost always used in conjunction with unit masonry such as brick, cut stone, or concrete masonry units ("concrete block").
Stretcher – The typical course style, masonry units are laid with their head (smallest surface) viewed from a side cross-section and the long, narrow sides forming the bulk of the visible course.
Header – Heads form the visible course and the long, narrow side is viewed from a side cross-section. This is often used to interlock a double wall (two adjacent wythes).
Rowlock – The long narrow sides are top and bottom; the heads visible. Single course. Above lintels. Between string courses. Occasionally the topmost course.
Soldier – Used mainly for decorative purposes as its upright nature does not lend itself to the compressive strength of a masonry unit and tends towards inward or outward lean (where mortar is used) or stress in successive courses. The long, thin sides are visible; the heads are top and bottom.
Sailor (rare) – Decorative, upright, weak and heat-permeable: The long thin sides are viewed from a side-cross section and the long thick sides are visible; the heads are top and bottom.
Shiner (rare) – Decorative, weak and heat-permeable. Long thin sides are top and bottom; the heads are viewed from a side cross-section.
A string course or band course is a thin continuous projecting course of brickwork or stone (typically of complementary or where near-white, of matching color) that runs horizontally around a building, typically to emphasize ceiling height and thus the junction between floors. Away from the top of the building it will represent a corbel table where it has any mock or physical supports (plainest corbels being dentils and most elaborate corbels being modillions), these effects are defined as a dentillated course and a modillioned course. Where just below the eaves or parapet roof wall the band course can be considered part of a cornice.