Final answer:
Omega-3 and omega-6 fatty acids are polyunsaturated fatty acids. The first double bond in omega-3 fatty acids is at the third carbon from the omega end, while in omega-6 fatty acids, it is at the sixth carbon.
Step-by-step explanation:
Omega-3 and omega-6 fatty acids are both polyunsaturated fatty acids. The main difference between them lies in the position of the first double bond relative to the methyl or 'omega' end of the carbon chain. Omega-3 fatty acids have their first double bond at the third carbon from the omega end, while omega-6 fatty acids have their first double bond at the sixth carbon from the omega end.