Acetic acid is another name for ethanoic acid. Because it partially dissociates into its constituent ions when dissolved in water, ethanoic acid is a weak acid. Acetic acid is an acid that ionizes very little in an aqueous solution. A fairly prevalent weak acid is acetic acid, which is present in vinegar.

${\mathrm{CH}}_3\mathrm{COOH}\rightleftharpoons {\mathrm{CH}}_3{\mathrm{COO}}^{-}+{\mathrm{H}}^{+}$