Example with a context:
I'll type cd ..\bin, I'll list the contents of the directory, and I'll see the new copy of Main.class. Now, because I've changed my current directory to bin, I can run the class from here, with java Main. Let's switch back to the source folder, cd ..\src. And I'm going to show you one incredibly valuable thing that running from the command line will let you do. I'll once again clear my screen.
What's the subject of that clause? Running from the command line? My understanding is the activity of running from the command line will let you do one incredibly valuable thing. But how would you classify this type of subject? Gerund?