Popular thought suggests that it is Fish Oil, and while that is certainly a fine way to achieve optimal amounts of these nutrients, there are other areas to look at. Mainly those which derive their content from Seeds and nuts. If you want to know more about omega 6 Alimentos, you can check out via the web.
Why would some choose something other than fish derived essential fatty acids? Perhaps they are vegetarian. This is a popular lifestyle choice and even though the vegetarian diet is healthy, most vegetarians would benefit from supplementation.
How can they do this? Essential fatty acids are available in whole food form from eating Almonds, Walnuts, and Flax seed. However, like most areas of nutrition, it is always advisable to supplement.
One of the primary concerns is that most people may eat what they consider to be adequate, and while it is certainly beneficial to derive a great deal of the derived nutrients from food, it is simply impossible to do so unless one changes one's entire diet.
Borage oil and Flax Seed oil both provide high amounts of Omega 3's and can be used for those who have objections to using fish oil. Many will use Borage Oil in conjunction with Flax seed so as to diversify the source of their Omega 3.
One reason for doing this is that certain plants contain different levels and different types of the nutrients. Just as in Fish Oil, which contains DHA in large amounts, Flax Seed offers alpha-linolenic acid. Someone who did not have objection would be wise to take a variety of sources so as to have a complete profile.