A cell wall is a rigid outer layer that surrounds the cell membrane of plants, bacteria, fungi, and some protists. It provides structural support and protection for the cell, helping to maintain its shape and prevent it from bursting or collapsing. The cell wall is made up of various compounds such as cellulose, peptidoglycan, and chitin, depending on the type of organism. It also serves as a barrier that regulates the movement of substances in and out of the cell.
