This document presents a summary of functions of glycolipids. Glycolipids are derivatives of ceramides and sphingosine that have carbohydrates directly attached. They play important roles in cell-cell interaction, structure of cell membranes, immune responses, blood types, surface receptors, and as parts of nervous and muscle tissue. Glycolipids are also involved in cell growth. Diseases related to abnormal quantities of glycolipids include ganglioside storage diseases and leukodystrophy.