Esters are made by reacting an alcohol with an organic acid. They are used in perfumes, and as solvents. Nail varnish dissolves in nail varnish remover, but not in water.
Volatile liquids evaporate easily. They readily change from a liquid to a gas. This is because there are only weak attractive forces between particles in the substance. These forces are overcome easily, so particles with enough energy can escape from the liquid.
This is the general word equation for the reaction that makes esters:
alcohol + organic acid → ester + water
methanol + butanoic acid…