I've read the lipids article on Wikipedia, but I couldn't understand the answer for my question and I'll explain why.
In biochemistry we have monomers and polymers while the monomer is the basic unit molecule for the polymere. In protein for example, we have amino acid that this is the basic unit of the proteins. Amino acid is characterized as structure of 4 groups: Alpha carbon, amine group, carboxylic group, hydrogen and R chain. this is the basic of all the amino acids.
But when we are talking about lipid as a main family of molecules (like what we have we have with protein) then I can not understand what is the "amino acids" (parallel) of them, i.e. what is the basic unit of the lipids and what is the structure.
Well, I could understand that the fatty acids are the analogous for the amino acids, but the problem is that fatty acids according the article (and other schemes that I saw on google pictures), they are considered as subgroup of the lipids, and that says that not all of the lipids are made of them. So I don't have clue for the answer to my question.