In rails, I can say
match 'user/:id/article/:id' => 'article#show'
Here the article#show, would use the Article controller, in the show action. And it would present the show view in the article folder. But what if I wanted to be specific and say show action in article controller, and present the xxx view in the xxx folder.
You specify what page is rendered in the controller.
Example:
That will render
app/views/products/show.html.erb.