What does this blinking orange light mean?

[DarkFlareGames]

On my PC case, there is an orange light that flashes, just below my headphone and microphone ports. I'm not sure what it means.

Here is my case: http://www.newegg.com/Product/Product.aspx?Item=N82E16811353061

I've also recorded a video of the flashing. It does this a lot but I never thought anything of it.
https://www.youtube.com/watch?v=gGdUGPZmMSY

My build:
CPU: FX 8320
GPU: GTX 960 2GB
MOBO: MSI 970A-G46
RAM: 4GB Kingston DDR3 1600mhz
Storage: Samsung 850 EVO 500GB SSD + 160GB HDD
PSU: http://www.newegg.com/Product/Product.aspx?Item=N82E16817438016
Case: (above)


I don't think it has anything to do with my PSU, as my buiild should never use more than 400 watts, even at maximum load. It was idle with nothing running when taking this video.

Could anyone help? Thanks in advance.

 

[ex_bubblehead]

It's the HDD access light. Shows you when a drive is being accessed.

 

[hapsoro]

it mean, your HDD or SSD working (reading+writing the data)

im not sure if that orange LED will works for SSD (I don't have SSD), but I'm sure it means what I'm said before....