Git is a free and open-source version control system. It facilitates collaborative work on software projects.
Beyond helping people collaborate on software development, git via Github is also now kind of a networking, professional development, and project visibility tool in that people can use public repositories as artifacts representing proficiencies.
Git (and Github) also enable continuous integration/continuous development (CI/CD) workflows, which basically means that software (e.g. websites, applications) can be continuously tested, built, and deployed from git repositories through the use of tools like Github Actions.
Fundamental Concepts
Repositories are kind of the foundational unit in git. They basically refer to the whole project itself.
Branches are kind of like independent timelines that track changes across files. A project will have a main (or master) branch that is the central timeline/path through the project, but there will often be other branches that diverge from this main timeline at a given point. By creating a new branch, a developer can ensure that any changes they make to this new branch won’t affect the master branch until they choose to merge the new branch back into the master branch. See the image below for a representation of this:
