The word absorption comes from the Latin word absorptio, which means “to absorb.”
In a broad sense, absorption refers to the act or process of absorbing or assimilating something. Absorption refers to the process of absorbing or assimilating substances into the cell or across tissues and organs in biology. Diffusion or osmosis are used to accomplish this.
Absorption via the skin, for example, is one method for chemicals to enter the body. The act of absorbing some hazardous chemicals via the skin (also known as dermal absorption) is one of the ways they might enter the body (others include inhalation and ingestion).
For some medicines, dermal absorption can be utilised as a route of delivery. The absorption of digested food, particularly via the intestinal wall, is another type of biological absorption (especially in the small intestine).
By diffusion or active transport, the digested food in the small intestine travels past the walls of the small intestine and into the blood vessels.
Absorption refers to the act or process of keeping light energy without reflection or transmission after passing through a material, as in the absorption of light by atoms, in other related fields such as physics.
Absorption in chemistry refers to the process by which one material permeates another, such as a liquid penetrating or being absorbed by a solid.