The difference between rough endoplasmic reticulum & smooth endoplasmic reticulum is : 1) Rough endoplasmic reticulum The rough endoplasmic reticulum looks rough under microscope because it has particles called RIBOSOMES on its surface. That ribosome are manufacturing site of proteins for cells. The rough endoplasmic reticulum is present around the nucleus. 2) Smooth endoplasmic reticulum The smooth endoplasmic RETICULUM (SER) looks smooth under microscope because they don't have ribosomes. The SER help in manufacturing of fat MOLECULES or lipids which are important for CELL function. These proteins & lipids help in building cell membrane. This process of building cell membrane is called membrane biogenesis. Explanation:The similarities between rough endoplasmic reticulum & smooth endoplasmic reticulum is :They both are channels for transport of material ( ESPECIALLY proteins) between various regions of cytoplasm & the nucleus. They also function as cytoplasmic framework providing surface for some biochemical activities of cell. I give your answer & I hope this will help you & please follow me I will definitely follow you.