What are the main properties of cell membranes?

All selective and controlled permeability, since they regulate the passage of solutes between two compartments that are separated by a cell membrane, certain particles can cross the membrane at certain times, which may be active or passive, this selective permeability is responsiblefor electrical polarity, due to the lipid properties most hydrophobic molecules can easily pass through the membranes whereas hydrophilic ones require channels or transporters, proteins integrated through the membrane, however they cannot transport large macromolecules, they are rather transported in vesicles through endocytosis, phagocytosis and exocytosis.