There are two main types of vesicles involved in this process:
* Pinocytic vesicles: These are small, membrane-bound sacs that form when the cell membrane invaginates and pinches off, enclosing a small amount of extracellular fluid. This process is called pinocytosis, which literally means "cell drinking."
* Phagosomes: These are larger vesicles that form when a cell engulfs a larger particle, such as a bacterium or a piece of debris. This process is called phagocytosis, which means "cell eating."
Both pinocytosis and phagocytosis are forms of endocytosis, which is the process of bringing material into the cell.
