Food is taken into the digestive system through the mouth by the process of ingestion.
These food particles are further broken down into simpler forms by the process of digestion with the help of enzymes.
Once digested, vital nutrients are absorbed by the body by the process of absorption.
Digested nutrients are then utilised for various purposes. This process is called assimilation.
Finally the undigested portions are eliminated from the body by the process of egestion.