Literally, the term means "little organs." Inside a cell, there are various little structures that perform specific functions, much like the multicellular organs of our body do. In the cell, these include generating energy (the organelle is the mitochondrion), making proteins (the organelles are ribosomes and Golgi apparatus), and others.
(or´ gan els´) [L.: little organ] • Organized structures that are found in or on cells. Examples: ribosomes, nuclei, mitochrondria, chloroplasts, cilia, and contractile vacuoles.