A hard drive activity light is a small LED light, usually positioned on the front of the computer case
on a desktop, near the keyboard on a laptop, or on some edge of a tablet, that lights up whenever the hard drive
or other built-in storage is being accessed.
Depending on the type of computer or device you have, the hard drive activity light may be any color but it's usually gold or yellow, and less commonly red, green, or blue. The light itself may be a small circle or it may be a special icon, often times a cylinder.
A hard drive activity light that is perpetually lit, especially when the computer isn't otherwise responsive, is often times a sign that the computer or device is locked up or "frozen" and should be restarted manually.
Also Known As: HDD LED
Examples: "Nothing was changing on the screen so I thought that maybe my computer had crashed. Though after seeing the hard drive activity light flashing on and off, I realized that my computer was working just fine, it was just taking a long time!"