You are now ready to build the AngularJS phonecat app. In this step, you will become familiar
with the most important source code files, learn how to start the development servers bundled with
angular-seed, and run the application in the browser.
In `angular-phonecat` directory, run this command:
```
git checkout -f step-0
```
This resets your workspace to step 0 of the tutorial app.
You must repeat this for every future step in the tutorial and change the number to the number of
the step you are on. This will cause any changes you made within your working directory to be lost.
If you haven't already done so you need to install the dependencies by running:
```
npm install
```
To see the app running in a browser, open a *separate* terminal/command line tab or window, then
run `npm start` to start the web server. Now, open a browser window for the app and navigate to
`http://localhost:8000/app/index.html`
You can now see the page in your browser. It's not very exciting, but that's OK.
The HTML page that displays "Nothing here yet!" was constructed with the HTML code shown below.
The code contains some key Angular elements that we will need as we progress.
__`app/index.html`:__
```html
My HTML File
Nothing here {{'yet' + '!'}}
```
## What is the code doing?
* `ng-app` directive:
The `ng-app` attribute represents an Angular directive named `ngApp` (Angular uses
`spinal-case` for its custom attributes and `camelCase` for the corresponding directives
which implement them).
This directive is used to flag the html element that Angular should consider to be the root element
of our application.
This gives application developers the freedom to tell Angular if the entire html page or only a
portion of it should be treated as the Angular application.
* AngularJS script tag: