Compare the role of the endoplasmic reticulum and the Golgi apparatus in the processing and transport of proteins within a cell.

The rough endoplasmic reticulum (RER) is the site where ribosomes synthesize proteins that are destined for secretion or for the plasma membrane.
The Golgi apparatus receives these newly made proteins from the RER, modifies them (e.g. adds carbohydrate groups), and packages them into transport vesicles.
The RER and Golgi work together by moving proteins in a vesicular pathway: proteins are transported from the RER to the Golgi in COPII‑coated vesicles, then from the Golgi to the cell surface or other organelles in COPI‑ or clathrin‑coated vesicles.
After leaving the Golgi, the proteins are delivered to their final destination, usually the plasma membrane or the extracellular space (or to lysosomes).