Tessellations 

A tessellation is a division of a plane (or flat surface) that results in a repeating pattern of shapes without any overlap or gaps. The simplest tesselation that I can think of is a chess board.

Made in southern Germany or Vienna about 1710. It was owned by a daughter of Franz Joseph I, Emperor of Austria at the time.

Fish scales look like tessellations. Why are they technically not tessellations? Highlight to find out why. --> A fish is not a flat surface, they overlap.