Modern life could not exist if it were not for electricity and electronics. The history of electricity starts more than two thousand years ago, with the Greek philosopher Thales being the earliest known researcher into electricity. But it was Alessandro Volta who created the most common DC power source, the battery (for this invention the unit Volt was named after him).
Direct current (also known as DC) is the flow of charged particles in one unchanging direction (most commonly found as electron flow through conductive materials). DC can be found in just about every home and electronic device, as it is more practical (compared to AC from power stations) for many consumer devices. Just a few of the places where you can find direct current are batteries, phones, computers, cars, TVs, calculators, and even lightning.