Omega 3
"Omega-3" refers to the position of the final double bond in the chemical structure, which is three carbon atoms from the "omega" or tail end of the molecular chain.
Since the human body can't produce omega-3s, these fats are referred to as "essential fats," meaning that you have to get them from your diet.
Omega-3 fatty acid (Alpha-linolenic acid) plays an important role in brain function and may help you fight against cardiovascular disease.