Monomer:

A monomer is a single unit of a polymer. In the case of lipids, the monomers are fatty acids. Fatty acids are long-chain carboxylic acids that consist of a hydrocarbon chain with a carboxyl group (-COOH) at one end.

Dimer:

A dimer is a molecule composed of two monomers joined together. In the case of lipids, a dimer can be formed when two fatty acids are linked together through a covalent bond.

Polymer:

A polymer is a large molecule composed of many monomers linked together. In the case of lipids, polymers are formed when multiple fatty acids are joined together through covalent bonds to form triglycerides, waxes, and phospholipids. Triglycerides are the main components of vegetable oils and animal fats and act as energy storage molecules, while waxes provide a protective coating for plants and animals. Phospholipids are essential components of cell membranes.

In summary, monomers are individual fatty acids, dimers are two fatty acids linked together, while polymers are long chains of fatty acids linked together to form various types of lipids, such as triglycerides, waxes, and phospholipids.