Illustrated Glossary of Organic Chemistry

Benzoic acid: Any molecule featuring a carboxylic acid functional group bonded to a benzene ring. Most commonly refers to the parent member of this family, C6H5COOH. Benzoate is the conjugate base of benzoic acid, or a molecule (usually an ester) containing the benzoate group (the group resulting from replacement of the carboxylic acid proton).

General benzoic acid structure   
Benzoic acid   
Benzoate anion, the conjugate
base of benzoic acid
Benzoate group

4-Fluorobenzoic acid
(para-fluorobenzoic acid; p-fluorobenzoic acid)
Acetylsalicylic acid
Methyl benzoate (an ester) contains
a benzoate group (in red).