You will find the
<head> of all of our view templates in the file
app/views/layouts/application.html.erb, which is a wrapper or "layout" that surrounds every view template that we send to our users.
If you go examine the
application.html.erb file that we got out-of-the-box when we generated the new application, you'll see that it includes all of the usual HTML boilerplate --
Notice the line that says
<%= yield %>. That is where the contents of our view templates get plugged in before the entire response gets sent to our users' browsers.
This is a great way to DRY (Don't Repeat Yourself) up repetitive markup like navbars, footers, links to stylesheets, etc. It's one of many advantages to using a dynamic framework like Rails over writing static HTML.