If you have a module you wish to use and that is only hosted on GitHub (which is an online Git service for sharing code using Git), you can create a local Git repository and make the GitHub module a submodule of your modules. Another use for a local copy is if the public module does not work entirely as you require, you can modify the public module in your local copy.
This workflow has issues; submodules are local to each working copy of a module. When working in an enterprise, the internal servers do not usually have access to public Internet services such as GitHub. To get around this access problem, you can create an internal Git repository that is a clone of the public GitHub repository (the machine which is performing the clone operation will need to have access to GitHub).
We'll start by cloning the public repository as our git user:
[root@stand git]# sudo -u git bash [git@stand ~]$ pwd /var/lib/git [git@stand ~]$ git clone --bare https://github.com/uphillian...