Git is a version control system. It tracks changes in sets of files for working in collaborative environments and allows you to go back to previous states. Github is the web-based service.
You can make a free account here, and make changes to files from your web browser, but for best results and maximum efficiency, you should also install git on your computer to access from the command line.
Github works kind of like a google doc, but not in real time. You take a copy of a file, make changes to it, and then "commit" or save your changes to the original file.
Once you have installed git, open up the terminal and navigate (using cd) to where you would like to make your first repository. A repository (often called 'repo') is a collection of files and their history, kind of like a folder on your computer.
To set the folder you are in as a git repository, use the command git init. You should get a message that says "Initialized empty Git repository in ..."
Next, make a file that you can add to your repository using a text editor like vim or nano. You can also make an empty text file using the command touch testfile.txt. You can use git status to see that your text file is listed as an untracked file.
To start tracking this file, you add it to the staging environment, or area where a file is stored temporarily before it is added to your repository. Use git add testfile.txt to add a file to the staging area, then use git status to see that your file is about to be committed.
Finally, use git commit -m "This is my first commit" to commit your file to the repository. You should always include a message at the end of your commit so that your collaborators will know what you are doing. Remember, your main collaborator is you two years from now!
One of the great things that git allows you to do is create branches to edit just one portion of the project without affecting the rest of the project. Once you are done editing your branch, you can merge your changes onto the master branch.
If you're working collaboratively on a project, it's a good idea to use GitHub. After logging in to GitHub, click the green button that says "New Repository" to create a new repository. Add a name and a description and then click "Create Repository". You can then upload the repository you just created by following the directions listed under "…or push an existing repository from the command line."
git remote add origin https://github.com/username/newrepo.git
git push -u origin masterNow you should see your testfile in your repository on GitHub!
You can also make and commit changes directly from GitHub. To get the changes you have made on GitHub back on your computer, use git pull origin master.
git clone <URL>
pulls a repository in using its URL that you get from github
git add <file>
adds a file to the staging environment
git status
shows what's different between us and the cloud
git commit -m "added file to thing"
commits change with a message
git push
syncs things on my machine to github.com
git pull
get the changes from github.com onto your computer
git log
lets you see all of the commits that have been made
esc :wq is how you get out of changes.
See this useful guide for more information on using git and github.