From NuGOwiki

The sphingolipids comprise a complex range of lipids in which fatty acids are linked via amide bonds to a long-chain base or sphingoid. Spingoid bases are long-chain aliphatic amines, containing two or three hydroxyl groups, and often a distinctive trans-double bond in position 4. To be more precise, they are 2-amino-1,3-dihydroxy-alkanes or alkenes with (2S,3R)-erythro stereochemistry, with various further structural modifications. A long-chain base, such as sphingosine, is the simplest possible functional sphingolipid, but ceramides, which contain a fatty acid linked by an amide bond, are not only important molecules in their own right, but are the precursors of phospholipids and glycolipids with an immense range of functions in tissues. These are quite distinct from the properties of the complex glycerolipids. For example, sphingomyelin has structural similarities to phosphatidylcholine, but has very different physical and biological properties, while the complex oligoglycosylceramides and gangliosides have no true parallels among the glycerolipids. See also the Lipid library link on sphingolipids.