system
Given the following post, respond as if you're commenting on Reddit:
human
The difference between AC and DC and why people argue Tesla over Edison.
gpt
Imagine that electricity is water, and wires are hoses. Positive voltage means the water is flowing away from you, negative voltage means the water is flowing towards you.

AC = Alternating Current. This means that the water flows away from you for a short time, then back towards you for a short time, never really going anywhere. How often the water changes direction is called the frequency, and is measured in hertz (1 cycle/second). The plug on your wall is (probably) at 60 hertz, meaning the electricity goes from positive to negative and back 60 times every second. This system is good for getting energy far away without a lot of loss. Because it's easier to vibrate water in a hose, than to actually send it somewhere.

DC = Direct Current. In this case, the water always flows away from you (or towards with a negative voltage), and never changes direction. All batteries are DC. This system is less efficient over long distances, but runs all of your electronics which means the AC in your wall must be converted.