Esters

An ester is a condensation product of an acid and an alcohol.
The formation of an ester from an acid and an alcohol is termed esterification.
During esterification a molecule of water is eliminated.
The formation of an ester from the acid and alcohol requires the use of heat and a dehydrating agent like conc. sulfuric acid. (Is there a difference between a dehydrating agent and a drying agent?)
Most esters are pleasant smelling compounds and are useful as constituents of perfumes, cosmetics and food flavouring agents.
Many esters are of medicinal importance.
Methylsalicylate is a constituent of many ointments like Vicks, Amrutanjan, Tiger Balm, Bengay and so on. (It is a muscle relaxant). Here is a list of some esters, their odours, the acid and alcohol from which they are derived.