Layouts, partials ...
views/layouts/application.html.erblayout false within a controller to prevent the default layout from being used.html.erb within the layouts
layout 'admin'@page_title<!--in application layout file-->
<title>Simple CMS Admin | <%= @page_title || "Admin" %></title>
<!--you can then set the `@page_title` in your template files-->
<!--show.html.erb-->
<% @page_title = "Subjects" %>
partials_form.html.erb
<%= render(:partial => "form") %>, (no underscore)<%= render(:partial => "form", :locals => {:varinpartial => localvar}) %>views directory)