A 10 to 200 nm protein-, cholesterol- and sphingolipid-rich microdomain of a membrane (e.g. plasma, endoplasmic reticulum, mitochondrial). These rafts are more ordered and thus denser than the lipid bilayer in which they are dispersed, and with which they exchange components. Through protein-protein and/or protein-lipid interactions between smaller rafts much larger platforms may be assembled to facilitate membrane functions such as trans-membrane transport and signal transduction. Because rafts can be extracted from cells with cold non-ionic detergents, they are sometimes referred to as detergent-insoluble glycolipid-enriched or detergent-resistant membrane domains, but such nomenclature is less than satisfactory because it focuses on the conditions of isolation and not on any intrinsic property of the rafts themselves.