The mosaic-makers had to be and had to be ready for work, which is why they also speak of mosaic artists or mosaicists. From small mosaic stones with an edge length of 1-2 cm or smaller, pictures and ornaments up to several meters in size were or will be created. Tesserae are rarely made of stones or semi-precious stones, mostly of glazed stoneware, porcelain or colored cast glass. In contrast, when the tiler speaks of mosaic, he means small-sized tiles between 50 x 50 and 100 x 100 mm. The mosaic stones are laid stone by stone in a mortar bed after a preliminary drawing, grouted and smoothed if necessary. In newer techniques, the mosaic is placed in its entirety in the mortar bed. For this purpose, it must first be applied to a grid or mirrored on paper or foil. From when exactly there were mosaics, can not be estimated so accurately. For most historians, however, the history of the mosaic begins with the Greeks.

These integrated first images and figurative representations in the mosaic. The first mosaics were pebble mosaics. The pebbles were embedded in mortar and used mainly for floor mosaics. The period of the pebble mosaic was from the 5th century BC and lasted about three centuries. From the beginning of the 2nd century, the Greeks began to process regularly hewn stone cubes (Opus tesselatum). The Romans spread Opus tesselatum throughout the Mediterranean. Among the most important early Roman finds is the Alexander mosaic (see photo) of Pompeii (around 100 BC). It consists of over 4 million stones and is 5.82 m by 3.13 m in size. If you wanted to build it, several mosaic artists would be busy for a whole year. From the 1st century BC, the black and white mosaic became more and more popular. It is also used to decorate niches, columns or vaults. The multicolor remains the mosaic art but still preserved.

In ArcGIS, you can mosaic a single raster dataset from multiple raster datasets. The figure below shows how to combine six adjacent raster datasets in a mosaic into one raster dataset. These overlap areas can be handled in a number of ways: for example, you can specify that only the data of the first or last raster dataset be preserved, you can merge the overlapping cell values ​​by using a weight-based algorithm, you can use the mean of the overlapping cell values, or you can choose the minimum or the maximum value. When creating a mosaic of discontinuous data, the Best, Minimum, and Maximum options give you the best results. The options blend and  mean are optimally suited for continuous data.

If the input rasters are floating-point rasters, the output rasters are also floating-point rasters. If all inputs are integer values ​​and the option “First,” “Minimum,” or “Maximum” is used, integer values ​​will also be output. The mosaic dataset allows you to select from many other mosaic methods that are applied to a dynamic mosaic or to an exported mosaicked raster dataset. These include the sorting by attributes, the use of a seamline and much more. There are also several options you can use to specify how a colormap might be processed. You can preserve the colormap of the first or last raster dataset used in the mosaic, or make sure all the colors in the last color map are unique.