Lipids are esters why

Dear student,
Please find below the solution to the asked query
 

Ester is the condensation product of an Carboxylic acid and alcohol. Reaction could be written as :

RCOOH (Carboxylic acid)  +  HO-R' (alcohol)  →  RCOOR' (Ester )  

Since lipids are formed by the combination of fatty acids (carboxylic acids present in oils and fats) with various alcohols through ester bonds, hence they are called as esters.

Hope this information will clear your doubts about the lipids.
If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.
Regards