What is this type of art called?

A mosaic is a piece of art or image made from the assembling of small pieces of of material such as stone, mineral, glass, tile, or shell. It is often used in decorative art or as interior decoration for ceilings, murals, and furniture embellishment. Most mosaics are made of small, flat, roughly square, pieces of stone or glass of different colors.

Mosaics have a long history, starting in Mesopotamia in the 3rd millennium BC. This type of art with patterns and pictures became widespread in classical times, both in Ancient Greece and Ancient Rome. Early Christian basilicas from the 4th century have been decorated with wall and ceiling mosaics. Mosaic art flourished in the Byzantine Empire from the 6th to the 15th centuries; that tradition was adopted by the Norman Kingdom of Sicily in the 12th century and by eastern Europeans. Roman and Byzantine influence led Jewish artists to decorate 5th and 6th century synagogues in the Middle East with floor mosaics.

Unlike inlay, mosaic pieces are applied onto a surface that has been prepared with an adhesive. Mosaic pieces are anonymous fractions of the design whose function is often the rendering of a whole portion of a figure or pattern. Once disassembled, a mosaic cannot be reassembled on the basis of the form of its individual pieces.