Fatty acids refer to long aliphatic hydrocarbon chains containing a carboxyl group at one end, which are organic substances. Low level fatty acids are colorless liquids with irritating smell, while high level fatty acids are waxy solids without obvious smell. It is a straight chain, acyclic carboxylic acid, such as formic acid, acetic acid, etc;
Higher fatty acids are carboxylic acids with many carbon atoms, generally more than 10 carbon atoms.
Fatty acids include higher fatty acids.