The digestive system processes food through a series of organs to break it down into nutrients the body can use. It begins with the mouth and includes the esophagus, stomach, liver, gallbladder, and small and large intestines. Food is broken down into smaller molecules as it passes through these organs to be digested and absorbed for energy and building materials. The digestive system is vital for breaking down food, absorbing nutrients, and eliminating waste from the body.