Mysterious Method added by Scaffold

I have created a blog by following the instructions detailed in the
now-famous blog screencast. Now, I'm attempting to increase my
knowledge of Rails by accomplishing that same feat in a more hands-on
way (i.e., without a scaffold). One perplexing issue that I have
encountered is that when I created the blog using a scaffold the
various template files that were created contained several instances
of mysterious code that looked similar to this:

<%= link_to 'Back', posts_path %>

and this:

<%= link_to 'Edit', edit_post_path(@post) %>

In the above, 'posts_path' and 'edit_post_path' appear to be methods;
but, I can't find where these methods are defined. If I insert
similar code into the blog that I created without a scaffold, Rails
complains about a missing method. Can someone please explain what the
story is on the mysterious methods?

Thanks for any input.

          ... doug

Try this for starters...