Question What are these buttons and lights do and mean on my PC case?

[hdmi123]

https://drive.google.com/file/d/1DivxgPaKHvhzpw2KPM0cnmSC5lhYB8Sd/view?usp=drivesdk i know the one on the left is the power button but what are the other 3 things?System was open when i took the pic

 

[ThatVietGuy]

Blue light probably is the power on light and red light is the hard drive activity, I think.

Smallest button on the far right is the reset button.