Rough Endoplasmic Reticulum
1.They have ribosomes attached to it
2.They help in the synthesis of proteins and enzymes
3.It is mainly formed of cisternae and few tubules

Smooth Endoplasmic Reticulum

1.It is mainly formed of cisternae and few tubules
2.They have no ribosomes attached
Helps in synthesis of glycogen and lipids
3.It is formed mainly vesicles and tubules.