This process of conversion of complex food substances to simple absorbable forms is called digestion.
The process begins at the mouth, called the buccal or oral cavity.
It passes through the oesophagus or food pipe, stomach, small intestines, large intestines, rectum, and ends at the anus.
Every organ performs a different function, and digestive enzymes and juices help in the digestion of food.
This initial stage of digestion begins in the oral cavity and completes in the large intestine.
The human body's digestive system is the sum of the gastrointestinal tract, also called the alimentary canal (tongue, liver, pancreas, etc.). Both together help in the digestion process.
The food particles gradually get digested as they travel through various compartments of the alimentary canal.