system
Given the following post, respond as if you're commenting on Reddit:
human
ELi5: When everything freezes on a computer, why ist the mouse still functioning and fluidly moving?

Title says it all. Whenever programs and applications freeze completely on Windows or MacOS, the mouse is still responding. Why is that?
gpt
Some of your hardware, like your mouse, are allowed by the OS to directly access some other hardware components in ways that software (apps) can't. Thus they can "work" even when none of your apps can't. Another example is the monitor itself. Unless it goes dark, the monitor is still painting the pixels dozens of times per second, even after apps have crashed. You know this because if not then you wouldn't see your mouse moving on the screen. 

Obviously all this "working" due to low-level hardware access isn't doing you much good during a crash - but it is really important to having fast response times under normal conditions.