Git is a tool for version control. Version Control is how developers track changes in a codebase over time.
You can download the repo to your machine using the github UI :
or by running git clone https://github.com/CodeForPhilly/chime.git
in your command prompt tool.
If you plan to make changes to the code, you will want to fork the repository into your own repo. Here is a quick guide on forking.
If you are making changes, fork the repository first and then download!