Click on the "Finder" app in your dock. Then click "Macintosh HD" At the bottom it should say "### available."

You can also DL [ Register or Signin to view external links. ] . It displays all of your memory info in an easy to read way. Showing you how much of you HD is music, or vids, of Docs, etc. I like it, it's very useful.

Let me know if that helps. I recommend getting Daisy Disk. Its really great.

This is a little over complicated, apple makes it easier for you. On other Unix based machines though you could type df -h into terminal.

Memory is what we call "RAM," or random access memory. Disk space is how much room you have for files on your hard drive(s). To find out how much memory you have and the speed, click the Apple in the top left corner and go to "About This Mac." To find out how much room for files there is on your hard drive, click on the Macintosh HD (or whatever you named it) in Finder and click "Get Info." It will say the size by "Capacity."

USE GOOGLE!!!!!!!