From the age of pushing On and Off buttons to simply touching a button that would perform both functions, without much thought, don't you think things have really evolved?
In this little toggle act, did you notice the symbol electronic gadgets carry to represent the power button - the small circle with a vertical line in it?
How did THAT orginate now? Apparently, the famous On/Off power symbol was the result of the logical evolution in user interface design. Hold on, we will break it down for you.
According to Wikipedia, "As technology became more ubiquitous, these English words were replaced by the universal numeral symbols 1 and 0 (typically without serifs) to bypass language barriers. This "1" and "0" standard is still used on toggle power switches."
Deriving itself from the Binary Number System, 1 (or the vertical line) stands for power On whereas 0 (or the circle) indicates power Off.
To create the symbol for a single On/Off button, the "1" and "0" symbols were super-imposedand merged each other to create the universally recognized power symbol currently in use.