Rough Endoplasmic Reticulum (RER)
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.
An endoplasmic reticulum (ER) in a cell is a system of membranes which is the site of manufacture of proteins and lipids.
The "rough" component of the term "Rough Endoplasmic Reticulum" or "RER" indicates that there are ribosomes attached to the surfaces of the endoplasmic reticulum.
See also the functions of cell organelles.