Here's the breakdown:

* Fatty acids are long chains of carbon atoms with hydrogen atoms attached. They are the building blocks of fats.

* Triglycerides are the most common type of fat found in our bodies and in food. They are made up of three fatty acids attached to a glycerol molecule.

Other substances that contain fatty acids include:

* Phospholipids: These are similar to triglycerides but have a phosphate group attached to one of the fatty acids. They are important components of cell membranes.

* Waxes: These are esters of fatty acids and long-chain alcohols. They are used as coatings for plants and animals.

* Steroids: These are lipids that have a specific ring structure. They include cholesterol, hormones, and vitamin D.

So, while fatty acids are the basic unit, they are combined with other molecules to form a variety of important biological structures.