in my  app/views/layout/posts.html.erb

<title><%= yield :title %>:: my fisrt rails blog :)</title>


in my app/views/posts/index.html.erb

<% content_for :title do %>
  <%= controller.action_name %>
<% end %>

and my _post partial

<% content_for :title do %>
  <%= post.title %>
<% end %>

different title tags

rails, ruby

Ruby