The main component of the cell membrane is phospholipids. These molecules are essential to forming the lipid bilayer that makes up the membrane, creating a semi-permeable barrier between the cell's interior and the external environment. Each phospholipid has a hydrophilic (water-attracting) "head" and two hydrophobic (water-repelling) "tails." This unique structure allows it to self-assemble into a bilayer, providing fluidity and flexibility while also enabling the passage of certain substances in and out of the cell. Proteins and carbohydrates are also embedded in the membrane, contributing to its functionality.