Pinocytosis is a cellular process in which cells take in small amounts of liquid and dissolved substances from their surroundings. This process is often referred to as "cell drinking" because it allows cells to absorb nutrients and other important molecules. During pinocytosis, the cell membrane invaginates, or folds inward, to form a small pocket that engulfs the liquid. This pocket then pinches off to create a vesicle, which transports the ingested material into the cell. This mechanism is essential for many types of cells, particularly those in the kidneys and intestines, where nutrient absorption is crucial. Pinocytosis is a form of endocytosis, which also includes other processes like phagocytosis, where cells engulf larger particles. By utilizing pinocyt