a small overview about what is git and why you should use it
Version control systems allow more people to work at the same project by managing the workflow seamlessly and saving every modification from every collaborator in a easy and understandable manner. This saves tons of time in the process of saving and checking if you are working with the latest version, allows for parallel development and shows the history of all changes to the project.
Git is only one possible version control system. However, due do its great community, design and ease to use, it is by far the most widely used.
Although easy to learn, the first steps may be not what you are used to, if you are not familiar with the terminal. But don't worry, soon they will come automatically and you will enjoy using them!
Git is the version control system, Github and Gitlab are hosted solution that allows you to use git to synchronize and work using their servers. You can also host your own git instance, see Gitea for an example
A very comprehensive written documentation for git your can find here:
A shorter documentation of the most important commands is given here:
And finally, one more tutorial on more advanced git concepts: