What is meant by a differentially permeable membrane?

A differentially permeable membrane, also known as a selectively permeable membrane, is a barrier that allows certain substances to pass through while restricting others. This property enables the selective transport of ions, molecules, and nutrients, crucial for maintaining cellular homeostasis. Such membranes are essential in biological systems, as they regulate the internal environment of cells by controlling what enters and exits. Examples include the plasma membrane surrounding cells and the membranes of organelles.