If you've ever used a Wi-Fi router to connect to the internet, you've probably wondered what all the blinking lights mean.

Blinking lights near an ethernet port on an ethernet switch - Kynny/Getty Images Have you ever looked at the back of your computer and noticed the lights where the cables are plugged into your PC?

Many households notice a small red light blinking on their digital electricity meter and often assume it signals a fault or unusually high billing. In reality, this tiny indicator is a built-in ...