Here's why it's important:

* Control of what enters and exits the cell: The cell membrane acts as a barrier, regulating the passage of substances into and out of the cell. This is crucial for maintaining the cell's internal environment and carrying out its functions.

* Communication with the environment: The cell membrane is involved in cell signaling and communication with other cells. It contains receptors that bind to signaling molecules, triggering specific responses within the cell.

* Structural support: The cell membrane contributes to the overall structure and shape of the cell.

In addition to the cell membrane, plant cells also have a cell wall, which is a rigid outer layer that provides structural support and protection. However, the cell wall is located outside the cell membrane.