Grain refers to the clumps of processed silver halide crystals that form the visible image on photographic film or paper. The size and distribution of the grain affect the image's texture, sharpness, and overall detail.
Finer grain produces smoother, more detailed images, while coarser grain can create a textured, artistic effect. Understanding grain is important for photographers when choosing film types, development processes, and printing methods to achieve the desired balance between image clarity and visual character.