Eclipse uses the notion of a workspace. The idea here is that if you are a professional programmer, you normally do things in one location. You, of course, have two jobs, but they would involve separate locations, and you would only work on one at once. The workspace is like this. In this case, it's just added confusion, and you can happily ignore it.
Eclipse also uses projects. These are not intrinsic to Java, but quite a few different tools use the same idea. This is a set of Java sources files that together do something useful. You might want to switch between projects or even work on two at once.