A concrete block is one of several precast concrete products used in construction. The term precast refers to the fact that the blocks are formed and hardened before they are brought to the job site. Most concrete blocks have one or more hollow cavities, and their sides may be cast smooth or with a design.The use of blockwork allows structures to be built in the traditional masonry style with layers (or courses) of staggered blocks. Blocks come in many sizes. In the US, the most common nominal size is 16 in × 8 in × 8 in (410 mm × 200 mm × 200 mm); the block measures a 3/8 in shorter, allowing for mortar joints.Bricks and blocks are components of durable masonry construction in which uniformly shaped individual units are laid in courses with mortar as the bed and binding material. They consist of high mass materials with good compressive strength formed into units that can be lifted and handled by a single worker.For most practical uses in today’s construction there is no difference. Both are blocks made out of cast concrete. Cinder blocks contain fly ash as an aggregate. That being said, most concrete contains fly ash in today’s construction of concrete masonry units.The common materials of masonry construction are brick, building stone such as marble, granite, travertine, and limestone, cast stone, concrete block, glass block, and cob. Masonry is generally a highly durable form of construction. A person who constructs masonry is called a mason or bricklayer.A brick is building material used to make walls, pavements and other elements in masonry construction. Traditionally, the term brick referred to a unit composed of clay, but it is now used to denote any rectangular units laid in mortar. Two basic categories of bricks are fired and non-fired bricks.