The power symbol has been around you since ages. Did you think about the reason why it’s designed so
Why Does The Power Symbol Have This Shape? Does It Depict Anything?
Probably, everyone in our vicinity is familiar with the iconic power symbol present on various devices and used to turn them on or off. The electronic devices in earlier times didn’t have the symbol on the buttons but had ‘on’ and ‘off’ written on power buttons (mostly toggle buttons).In 1973, the International Electrochemical Commission first included the symbol to their set of graphics symbols for use on electronics. The power button symbol isn’t just some random graphics; it signifies something. The circular part of the button represents the binary number 0 (off state); the line represents the binary number 1 (on state).
The reason that the power button symbol was brought to existence was to lift the language barrier, which was posed when the ON and OFF English text was used on electronics. Now people, regardless of the language they understand, can recognize the power button. The power symbol is also being used in digital users interfaces as well.
The power symbol you see more frequently has the line half inside the circle. This means the power button won’t cut off the power completely but put it in standby mode. So, technically it’s known as the standby symbol.
The toggle or rocker buttons still have the line outside the circle which means switching the button on either side will turn the power ON/OFF completely. A variant having the line inside the circle is present on the push-type button which turns the power ON/OFF completely.