Wax has traditionally referred to a substance that is secreted by bees (beeswax) and used by them in constructing their honeycombs.
In modern terms, wax is an imprecisely defined term generally understood to be a substance with properties similar to beeswax, namely
Waxes may be natural or artificial. In addition to beeswax, carnauba (a vegetable wax) and paraffin (a mineral wax) are commonly encountered waxes which occur naturally. Ear wax is a sticky substance found in the human ear. Some artificial materials that exhibit similar properties are also described as wax or waxy.
Chemically, a wax may be an ester of ethylene glycol (ethane 1,2-diol) and two fatty acids, as opposed to a fat which is an ester of glycerin (propane 1,2,3-triol) and three fatty acids. It is a type of lipid.