Depending on your operating system, find the shell of your preference. Here are some suggestions.
- [Terminal](http://blog.teamtreehouse.com/introduction-to-the-mac-os-x-command-line) on Mac OSX
- [GitBash](https://msysgit.github.io) on Windows
- [Linux Terminal](http://www.howtogeek.com/140679/beginner-geek-how-to-start-using-the-linux-terminal/) on Linux
## Check if Git has already been installed
Git is usually preinstalled on Mac and Linux.
Type the following command and then press enter:
```
git --version
```
You should receive a message that will tell you which Git version you have in your computer. If you don’t receive a "Git version" message, it means that you need to [download Git](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git).
If Git doesn't automatically download, there's an option on the website to [download manually](https://git-scm.com/downloads). Then follow the steps on the installation window.
After you finished installing, open a new shell and type "git --version" again to verify that it was correctly installed.
## Add your Git username and set your email
It is important because every Git commit that you create will use this information.
On your shell, type the following command to add your username:
```
git config --global user.name ADD YOUR USERNAME
```
Then verify that you have the correct username:
```
git config --global user.name
```
To set your email address, type the following command:
```
git config --global user.email ADD YOUR EMAIL
```
To verify that you entered your email correctly, type:
```
git config --global user.email
```
You'll need to do this only once because you are using the "--global" option. It tells Git to always use this information for anything you do on that system. If you want to override this with a different username or email address for specific projects, you can run the command without the "--global" option when you’re in that project.