what's the different between pinocytosis and phagocytosis?

pinocytosis is a cellular process that permits the active transport of fluid from outside the cell through the membrane surrounding the cell into the inside of the cell. in pinocytosis, tiny incuppings called caveolae (little caves) in the surface of the cell close and then pinch off to form pinosomes, little fluid-filled bubbles, that are free within the cytoplasm of the cell.

phagocytosis (literally "cell-eating") is a process which is used by cells to engulf and subsequently ingest particles of nutrients or bacteria. this process is a very important part of cell function, allowing cells to grab vital nutrients and allowing the body to protect itself from harmful bacteria. a cell which specializes in phagocytosis is known as a phagocyte. this process is one among a family of processes collectively referred to under the blanket term ?endocytosis,? which refers to any sort of ingestion of material by a cell. the opposite, of course, is exocytosis, the expulsion of unwanted material from a cell.

In simple terms,
pinocytosis = cell drinking;  
phagocytosis = cell eating