Fork me on GitHub

Git introduction: (Optional) In-browser session


Teaching: 20 min
Exercises: 0 min
  • How can I contribute to repositories without command line?
  • See an existing repository in action.
  • Browse the history.
  • See the big picture without going into command line details.

In-browser session

  • We will explore and visualize an existing Git repository on GitHub and make small changes to it.
  • The goal of this episode is not to teach GitHub, but rather to get a glimpse of the wider picture.


  • Often our first contact with Git is an existing repository, and it is relatively easy to contribute to them.
  • The existing repository is often on GitHub (but this demonstration applies equally well to GitLab or Bitbucket).
  • Most of the Git commands we are about to learn can be done in the browser, which is a more intuitive way to get started.
  • It’s good to see the social aspect to know what our end goal is.

Do not worry

  • If you are new to version control, don’t focus on what we do. Focus on what comes out of it.
  • When browsing a GitHub repository we are looking at two layers. Later we will explain what is in the Git layer and what is in the GitHub layer.


We start with an existing repository that contains a couple of commits and two branches with some easy code.

The project contains several obvious issues (bug in code, typo in documentation, missing license file, outdated usage example).

  • History
  • Reproducibility
    • Find a bug in and use annotation to check when precisely the bug got introduced.
    • Discuss the enormous value of the annotation feature.
  • Collaboration
    • You can refer to code portions (so much simpler to send a link rather than describe which file to open and where to scroll to).
    • Identify other issues (bug in code, misleading comment, typo in documentation, missing license file, outdated usage example).
    • Instructors use the browser to create a branch and make a commit to an existing project: Instructors will make a change concurrently, one of them (the presenter) will do one change on the screen. Also experienced participants can already join.
    • Make a merge request (it’s easy in browser, and shows cool stuff).
    • Browse the network.
    • See contributors.
  • Releases

While some of these are GitHub features, it all can be done on other sites, or by yourself without GitHub at all.