Grain and Grain Products

The word grain has several meanings, most being descriptive of a small piece or particle.

Particle-related

The primary definition is the agricultural one, with the others derived from it.

• In agriculture, a grain is the seed of a grass, a simple dry fruit technically called a caryopsis. Such crops are often called cereals. Grain can also refer to other types of small seeds, though this is technically less correct.
• In units of measurement, the grain is a unit of mass equal to 64.79891 milligrams. It was originally based on the weight of one grain of barley. It was used in the past for older drugs such as aspirin, for bullets, and for precious metals.
• In geology, a grain is a single particle of rock or other material, such as sand or salt; see grain size.
• In materials science (especially metallurgy), a grain is a single crystal inside solid-state matter, also referred to as crystallite — related to the obsolete term "corn" as in corned beef.
• In photography, the fineness of image resolution for photographic film (i.e., graininess of a picture), originally related to the (crystallographic) grain size of silver iodide.

Others

• In wood, grain describes the alignment and texture of the wood fibres. This is often important in its effect on woodworking techniques (e.g. going against the grain).
• In golf, the direction in which individual blades of grass lie, usually in reference to a putting green.
• In textiles, grain refers to the direction of woven fabric's warp (lengthwise) and weft (crosswise) threads.
• In rocket science, grain refers to the solid propellant of a rocket (either solid fuelled or hybrid), more or less a hollow cylinder, sometimes textured inside, and possibly very large.
• In computer science, grain refers to the size of code executed by a thread or process before it is interrupted in a multiprocess system (its granularity). Thus we have fine-grained and coarse grained parallelism.
• In physics, a fine-grained description is one which contains a lot of small-scale detail. Reducing the amount of detail gives a coarse-grained description.
• Grain may refer to the place Isle of Grain in Kent, England, on which lies the village of Grain, Kent.
• Grain is one of the stocks in the game Stock Ticker.
• In music, see granular synthesis.