What is a semi-permeable membrane? Give examples.

(N/A) semi-permeable membrane is a type of biological or synthetic membrane that allows certain molecules or ions to pass through it by diffusion or specialized facilitated diffusion.
In the context of osmosis,it is a membrane that allows only the solvent molecules (e.g.,$H_2O$) to pass through while blocking the passage of solute molecules.
Examples:
$1$. Natural membranes: Pig's bladder,parchment paper,and animal skin.
$2$. Synthetic membranes: Cellophane,copper ferrocyanide $[Cu_2[Fe(CN)_6]]$,and cellulose acetate.