The glycocalyx is a fuzzy-appearing layer found on the surface of many cells, primarily composed of glycoproteins and glycolipids. This structure plays a crucial role in cell recognition, protection, and communication. It helps cells adhere to surfaces and can also act as a barrier against pathogens and mechanical stress. In addition to its protective functions, the glycocalyx is involved in various biological processes, including cell signaling and immune responses. It is particularly important in endothelial cells lining blood vessels, where it helps regulate blood flow and maintain vascular health.