Gray toothed wheel on Mac Finder What is the meaning of the gray toothed wheel on Mac Finder located right bottom?

What is its name?
It’s called an asynchronous progress indicator and serves to tell you that Finder is still loading the contents of the window, enumerating files and folders (and calculating sizes if you have that option turned on). This would suggest that the external drive you have opened is still being read from and not all the files/folders are shown yet in the window.