What is a "stuck" process?
The significance of stuck is that the process is not running while in a state that is uninterruptible while it waits for I/O. There’s nothing wrong, just that the kernel has accepted an I/O and it’s “stuck” waiting for that response before it can be paused or sent a signal to exit (or more likely continue to run normally).

How does &#39;stuck&#39; (in results of &#39;top&#39;) relate to &#39;not responding&#39; (in Activity Monitor), &#39;spin&#39; or &#39;hang&#39;?