The cell membrane is.

a thin, semi-permeable membrane that surrounds the cytoplasm of a cell. It acts as a barrier, controlling the movement of substances in and out of the cell. The cell membrane is made up of a double layer of phospholipids with embedded proteins and cholesterol molecules. It also contains carbohydrates that help with cell recognition and communication. The cell membrane plays a crucial role in maintaining the cell's internal environment and allowing for communication with other cells.

A semipermeable barrier