The gallbladder concentrates and stores bile as a pear-shaped sac which it can release to help digestion after a fatty meal.
Lipids is a general term for a group of fat-soluble molecules that includes fats, oils, waxes, cholesterol, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, etc.
Lipids perform the functions of energy storage, building cell membranes, and acting as signaling molecules. Although some lipids are an absolute necessity for life there are some such as cholesterol, which when present in high levels, can lead to health conditions.