Single-phase refers to a type of electrical power system that uses a single alternating current (AC) waveform. It is commonly used in residential and light commercial applications, providing a straightforward and efficient way to deliver electricity. In a single-phase system, the voltage fluctuates in a sinusoidal manner, typically at a frequency of 50 or 60 hertz, depending on the region. This system is ideal for powering small appliances and lighting, as it is simpler and less expensive to install than multi-phase systems. However, for larger industrial applications, three-phase power is often preferred due to its ability to deliver more power and maintain a more constant energy supply.