Tessellation is a pattern of geometric shapes with no overlaps and no gaps. Tessellations are used to tile a flat surface that can extend infinitely in all directions. In 4000 B.C., Sumerians used these figures made of clay tiles for wall decorations.
Regular tessellations are made up of identical tiles of regular polygons with similar vertices. Semi-regular tessellations, on the other hand, are combinations of two or more regular polygons with vertices or corners having uniform arrangement.
The term "tessellation" in computer graphics refers to the structure of information essential in rendering surfaces of objects to give a realistic three-dimensional look.