Our apps are nothing more than a collection of URLs that we decide to allow users to access:
mydomain.com/products
mydomain.com/photos/193
mydomain.com/signin
So remember: everything always starts with a route between a URL we want to support and a Ruby method that will be responsible for generating a response to the user's browser.
In order to support a URL in your app such as http://localhost:3000/signin
, there are a lot of dots to connect!