Eukaryotic cells have a variety of specialized structures called

Eukaryotic cells have a variety of specialized structures called organelles.

Organelles are membrane bound structures or compartments  of a cell which perform special functions. They are the different parts of a cell which are separated by a membrane from the rest of the cell.

In  a eukaryotic cell are found many organelles  such as the nucleus, endoplasmic reticulum, Golgi apparatus and mitochondria.

The word organelle literally means little organ and just as the body has various organs, so too does the cell have little organs that are used to perform special functions to support the cell.