Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane, and bringing it into the cell. Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell. The main similarity is that both exocytosis and endocytosis are involved in transporting big molecules across the membrane using a vesicle and needs energy. The basic differences are that : 1) Endocytosis brings materials to the inside of the cell while exocytosis takes them out. Exocytosis, on the other hand, is described as the process of fusing vesicles with the plasma membrane to release their contents to the external environment of the cell.