What is critical micelle concentration (CMC)?

Critical micelle concentration (CMC) refers to the specific concentration of amphiphilic molecules in a solution at which micelles start to form. At this concentration, surfactant molecules aggregate to form micelles, making the solution thermodynamically stable. 

Below the CMC, surfactants primarily exist as individual molecules, while above the CMC, additional surfactant molecules contribute to micelle formation. The CMC is a key property of surfactants and influences various physical attributes such as surface tension, osmotic pressure, detergency, and conductivity.