Fats are made up of carbon, hydrogen, and oxygen; the way the carbon and hydrogen are chemically structured determines if they are unsaturated or saturated.
Saturated fats are the least healthy fats; they are often found in animal sources, such as butter, lard, full-fat dairy products, visible fat in meats, and processed meats.
Trans fats are vegetable oils that have been processed to make them hard; this is done by passing hydrogen through the liquid oil, a process called hydrogenation, which turns the liquid oil into a lump of fat.
Omega 3 has health benefits such as helping with depression and eye development in infants; sources of omega-3 are salmon, mackerel, trout, and sardines.
Invisible fats are fats that are within products, such as milk, cheese, ice cream, etc., whereas visible fats are fats you can see, such as the rind on bacon.
High-density lipoprotein (good cholesterol) can carry cholesterol from other parts of the body to the liver, and then the liver processes the cholesterol out of the body.