Alternating current & direct currents differ in that electrons flow back & forth in AC, but only in one direction in DC. Because AC can tolerate more voltage, it loses less energy over long-distance progression.
As a result, AC is commonly used to supply power in most homes and buildings. Hence most home appliances run on AC; Conversely, they must convert the AC power supplied to the building or house into DC to power the device.
Personal computers typically run on DC and include a rectifier to perform this conversion. In this case, the rectifier is referred to as a regular power supply.