Active absorption :- It is a up stream absorption in which use of specified Protein along with ATP is used to absorb substance like ions etc. Active absorption occur against the concentration gradient
Facilitated diffusion :- It is a down stram absorption in which use of special protein is there but no ATP is used to absorb substance like water in plant cell . Facilitated diffusion occur through concentration gradient
Diffusion :- It is a down stream absorption in which no requirement of special protein and ATP molecules is there to absorb substance like glucose etc . Diffusion occur through concentration gradient.