We have rough and smooth endoplasmic reticulum as the two types of endoplasmic reticulum. They are different from each other in that the rough endoplasmic reticulum has ribosomes on its surface while the smooth reticulum does not...The two also carry out different functions,having ribosomes on their surface,the rough reticulum is in charge of protein synthesis whereas the smooth endoplasmic reticulum is in charge of the synthesis of lipids