A cell is the basic unit of living organisms that is capable of reproducing itself exactly. That is, although eukaryotic cells (such as plant cells and animal cells) contain components, which are called organelles, those components do not reproduce themselves independently of the cell of which they are a part.
The Golgi Apparatus is also known as the Golgi complex, the Golgi body, or simply the Golgi.
It consists of a collection of vesicles and folded membranes. These are usually connected to an endoplasmic reticulum (ER) because the golgi apparatus stores and then transports the proteins produced in the ER.
The Golgi apparatus modifies, sorts and packages macromolecules for delivery to other organelles or secretion from the cell via exocytosis.
Due to its functions of storing and transporting proteins, the Golgi apparatus may be creatively thought of as the "Post Office" of the cell. It is particularly well developed in cells that produce secretions.
See also the functions of cell organelles.