The Cell Membrane is a vital structure that surrounds and protects the cell, acting as a barrier between the internal environment and the outside world. It is primarily composed of a phospholipid bilayer, which allows selective permeability, meaning it controls what enters and exits the cell. This selective nature is crucial for maintaining homeostasis and supporting cellular functions. In addition to its protective role, the Cell Membrane is embedded with proteins that facilitate communication and transport. These proteins help the cell respond to external signals and interact with other cells, making the membrane essential for processes like cell signaling and nutrient uptake.