Tessellation is the tiling a surface (in this case a flat surface) without gaps and overlaps. This concept is very important since many of the floors and walls are tiled nowadays. But tessellation is a lot more than that. It actually obeys the law of mathematics particularly angles.
The plane can be tiled with just one polygon as shown below. Some of such types of polygons are squares, triangles, and hexagons.
Can you think of other shapes that can tile the plane individually?