First try.

A repository is usually used to organize a single project.

Branching is the way to work on different versions of a repository at one time.

By default your repository has one branch named master which is considered to be the definitive branch. We use branches to experiment and make edits before committing them to master.

Here at GitHub, our developers, writers, and designers use branches for keeping bug fixes and feature work separate from our master (production) branch. When a change is ready, they merge their branch into master.

On GitHub, saved changes are called commits.

Each commit has an associated commit message, which is a description explaining why a particular change was made. Commit messages capture the history of your changes, so other contributors can understand what you’ve done and why.

Pull Requests are the heart of collaboration on GitHub. When you open a pull request, you’re proposing your changes and requesting that someone review and pull in your contribution and merge them into their branch. Pull requests show diffs, or differences, of the content from both branches. The changes, additions, and subtractions are shown in green and red.

Look over your changes in the diffs on the Compare page, make sure they’re what you want to submit. When you’re satisfied that these are the changes you want to submit, click the big green Create Pull Request button.

In this final step, it’s time to bring your changes together – merging your second branch into the master branch.