Alternating Current (ac) and Direct Current (dc)

Alternating Current (AC)

Alternating Current (AC) is a type of electrical current in which the direction of the flow of electrons switches back and forth at a regular rate.
AC is the form of electricity that is delivered to businesses and residences; most household outlets provide AC electricity.
The main advantage of AC is that it’s possible to transmit over large distances without losing too much energy.
In AC, the amplitude of the current varies sinusoidally and corresponds to a specific frequency, usually 50 or 60 Hz.

Direct Current (DC) is electrical current which flows consistently in one direction.
DC is the type of electricity made by a battery (with definite positive and negative terminals), or the type of charge generated by solar cells.
DC power is safe to touch up to about 50 volts, and is used for most small appliances and electronic devices.
Unlike AC, DC does not switch direction and stays constant; the voltage remains constant unless the circuit is broken.

AC can be converted into DC using a device called a rectifier, and DC can be changed into AC using an inverter.
Most home electronics use DC power while household outlets produce AC power. This necessitates that AC power be converted to DC in order to power electronic devices, typically done with a AC-to-DC adapter.
Direct current is used in objects such as flashlights, cell phones, laptops, and other devices that use a power supply.
In contrast, alternating current is used in powering buildings, light bulbs, and other more powerful devices.