Fatty acids are molecules consisting of long chains of carboxylic acid, which is an organic acid consisting of carbon, oxygen, and hydrogen atoms. The "backbone" of the fatty acid chain is a string of carbon atoms; the oxygen and hydrogen atoms "protrude" out from the carbon backbone. Most fatty acids are chains of between four and 28 carbon atoms.
Fatty acids are either saturated or unsaturated, a terminology that refers to whether the carbon atoms in the fatty acid chain are bound to each other by single or double bonds. Saturated and unsaturated fatty acids have different effects on health.
Some unsaturated fatty acids are referred to as "essential fatty acids," which means they are essential to life but cannot be manufactured in the body. So essential fatty acids must be obtained from the diet. Omega-3 fatty acids are essential fatty acids.
