The terms “digestion” and “absorption” are not interchangeable in terms of the body’s internal processes.
Digestion essentially is the decomposition of molecules for absorption and is represented by acts such as chewing and swallowing. It typically refers to the physical breakdown of molecules, while absorption is more chemically associated with the body.
Absorption refers to the process in which digested materials are taken into the lymphatic system, better known as the bloodstream, and received by the body to maintain homeostasis through the necessary resources (vitamins, fats, carbohydrates, etc.).
In terms of the body, digestion precedes absorption. This renders the two terms to not be interchangeable, as one is more involved physically and the other is more involved chemically.