If you're relatively new to using version control, there may be one technique you've yet to get a grip on. In this new post on SitePoint.com's Web blog they introduce you to using the "diff" functionality to discover differences between versions of code.

Every project is made up of countless little changes. With a little luck, they will finally form a website, an app, or some other product. Your version control system keeps track of these changes. But only once you understand how to read them will you be able to track your project’s progress. Using the example of Git, the popular version control system, this article will help you understand these changes.

They include several screenshots and line-by-line descriptions of what each part of the output of the "git diff" command is. There's also a brief description of what each of the sections contains and how to inspect both committed and non-committed changes. There's even a link to a list of other applications that may help provide a clearer picture of the changes rather than just the command line output.