The Golgi apparatus is a tiny part of a cell that does a big job, modifying, packaging, and transporting proteins.
Most eukaryotic cells, or cells that have a nucleus, contain the Golgi apparatus. It works like a tiny processing and sorting factory, receiving proteins, modifying them if necessary, and packaging them in sacs known as vesicles. The proteins are then delivered wherever they're needed, both in and out of the cell. The Golgi apparatus gets its name from the scientist who first identified it in 1897, Camillo Golgi.