Solids are a state of matter that are usually highly ordered.
The chemical and physical properties of the solid depend on the detail of this ordering. In carbon, the bonding in the solid forms is highly directional and dictates the long ranges order. In metals, the bonding is non-directional and often the solid structure is determined by atomic 'packing'. The description of the ordering of atoms in a solid comes from simple concepts of how identical objects stack in an array. The angles, edge length, and atomic positions of the repeat unit are sufficient for the visualization of the entire infinite array in the solid.