Dear student
The process of taking food into the body is called ingestion.
The process of breaking down complex substances into simpler once to make absorption easier is called digestion.
The process by which digested food is absorbed by small intestine is called absorption.
The process of expelling ungested food substances out of the body is called egestion.
The absorbed food is transported via blood vessels to different organs of the body where they are used to build complex substances is called assimilation.
Regards