From Scroll Saw Wiki
Intarsia is a form woodworking similar to marquetry. It uses various sizes, shapes, and species of wood fitted together to create a mosaic-like picture. Intarsia relies on grain direction and different species of wood to give the picture color and depth. Each piece is shaped and either sanded down or shimmed to create depth similar to a relief carving. The pieces are then assembled and glued to a plywood backer and finished with a protective coat, being careful not to alter the wood's natural color.
The technique of intarsia is believed to have been developed in Siena, Italy in the 13th century by crafters using inlays of ivory inserted into wood. Examples can also be found using wood inlayed into wall murals, table tops and other furniture. The art was perfected in Siena and in northern Italy during the fifteenth and sixteenth centuries. Soon it spread to German centers and introduced into London by Flemish craftsmen in the late sixteenth sentry. After 1620, marquetry replaced intarsia.
It is thought that the word 'intarsia' is derived from the Latin word 'interserere' which means "to insert."