Nice work! In three commands, you built a working Rails app that displays the Rails default page. How does it work?

1. The rails new command created a new Rails app named MySite. It generated a number of files and folders that we will use to build the app. In the Code Editor, click on the folder icon to see these files and folders. We'll see what these files and folders are for in the next exercises. The rails new command is the starting point of every Rails project.
2. The bundle install command installed all the software packages needed by the new Rails app. These software packages are called gems and they are listed in the file Gemfile.
3. The rails server command started the Rails development server so that we could preview the app in the browser by visiting http://localhost:8000. This development server is called WEBrick.