What are Tessellations
The word 'tessera' in latin means a small stone cube. They were used to make up 'tessellata' - the mosaic pictures forming floors and tilings in Roman buildings
Notice, in the example at right, that the artists used many small square tiles to create one big picture of a bull.
Nowadays, the term "tessellation" has become more specialized. Its meaning has changed. Now it means pictures or tiles that aren't just square-shaped. Usually, particularly in Esch-style tessellations, the tiles aren't square. The individual tiles are the shape of animals, people, and things. Nowadays, when we say "this is an animal tessellation", we don't see lots of little tiles making a big picture of an animal. Instead, each little tile is a little picture of an animal. The tiles cover a surface -- usually a 2D (i.e., flat) plane -- in a symmetrical way without overlapping or leaving gaps. You can see examples in the many art galleries here at Tessellations.org.
A Roman floor mozaic:
Big picture, small square tiles.
Big picture-shaped "tiles".