system
Given the following post, respond as if you're commenting on Reddit:
human
Why do some electrical plugs need to be plugged in the right way (i.e. turned "right side up") and why does it not matter for some of them?
gpt
ELIF version - In the united states one blade of the plug is wider than the other so it must be inserted the correct way. Other countries achieve this with other keying systems. These plugs are polarized meaning one connector is the neutral and the other is the energized connector. These polarized plugs allow the device manufacturer to design the product so they will know their power switch will always be connected to the energized lead. So when you turn it off there really is no power getting into the device.