A rectangular array of squares or rectangles of equal size, such as in a crossword puzzle.
A tiling of the plane with regular polygons; a honeycomb.
A system for delivery of electricity, consisting of various substations, transformers and generators, connected by wire.
A system or structure of distributed computers working mostly on a peer-to-peer basis, used mainly to solve single and complex scientific or technical problems or to process data at high speeds (as in clusters).