This is supposed to be a short introduction to Git and an overview of related tutorials and tools.
What is Git?
Git is not Dropbox. That means Git is not syncing or backing up automatically. You decide when and what changes you want to write to the Git history.
Git is not GitHub. Git is a tool that is independent of any company. What companies like GitHub/GitLab/Bitbucket sell is a service for you to host your repositories on the public internet to share and collaborate with the world.