These fats are considered essential because they are necessary for the body and must come from the diet.
The three most nutritionally important omega-3 fatty acids are alpha-linolenic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega 3 fatty acids are important in reducing inflammation, healthy blood clotting, maintenance of cell membrane fluidity so that nutrients/waste/and other biochemical compounds such as hormones and cell signaling can easily move in and out of the cells, and reducing cancer cell growth. Great food sources of omega 3 fatty acids are flaxseeds, salmon, walnuts, soybeans, sardines, to name a few. Linoleic acid is found in high concentrations in corn oil, safflower oil, sunflower oil, and canola oil. Most people get much more linoleic acid in the diet so it is a good idea to focus on getting more of the Omega 3 rich foods. Some monounsaturated food sources are olives, olive oil, avocados, beef tallow, cashews, macadamia nuts, and pecans which are necessary for heart health and have been found to lower LDL cholesterol and possible increase HDL cholesterol. Natural nuts especially are a great way to include the fats in your diet and are also high in minerals and vitamins.
The bottom line is to get a variety of fats from whole food sources and for the most part, avoid processed, packaged, and fat laden fast foods.