The main component of cell membranes is phospholipids. These molecules are arranged in a bilayer, creating a semi-permeable membrane that separates the interior of the cell from its external environment. Phospholipids have hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails, allowing for the formation of this unique structure. Additionally, cell membranes contain proteins, cholesterol, and carbohydrates, which contribute to their fluidity, functionality, and communication capabilities. The integrity and properties of cell membranes are essential for cellular homeostasis and the communication between cells.