An organelle found in all eukaryotic cells and absent from prokaryotes such as bacteria. The Golgi apparatus is named after the Italian histologist Camillo Golgi, who visualized an “internal reticular apparatus” by light microscopy in 1898. This organelle consists of flattened membrane-bounded compartments known as cisternae. In most cells, the Golgi cisternae are organized into stacks. Different cell types contain from one to several thousand Golgi stacks. The Golgi apparatus sorts newly synthesized proteins for delivery to various destinations, and modifies the oligosaccharide chains found on glycoproteins and glycolipids.