Omega 3 fatty acids are a class of essential fatty acids(meaning we need to get them through our diets and cannot produce them ourselves internally) that have a wide variety of health benefits. Omega 3 fatty acids are primary known for their anti-inflammatory and cholesterol lowering properties but have also been studied in diabetes, cancer and autoimmune conditions to name a few.
Most people think you can only get them from fish but high quality vegetable sources can also be found.
High in flax seeds and walnuts these can be great options to supplement if you choose not to use a fish source. Just be very mindful of quality since these oils oxidize(go rancid) very quickly if exposed to too much heat or light.