How knows my paths in link_to? If I do not defined.

Hello,
It´s my first post here. :slight_smile:
I´l following the guide of Ruby, but I need to know how the Ruby knows
my path to other pages if I did not define anything, like this:

app/views/posts/index.html.erb:
    <td><%= link_to 'Show', post %></td>
    <td><%= link_to 'Edit', edit_post_path(post) %></td>

Other path(home/index.html.erb):
<%= link_to "My first blog in Ruby on Rails", posts_path %>

I need help to know how Ruby knows the path of "post",
"edit_post_path(post)" and "posts_path"?

Thank you all!

ps:
The link that I´m following:
http://guides.rubyonrails.org/getting_started.html#creating-the-blog-application

This is the convention over configuration thing.
Once you define your map.resources in routes.rb, rails does the rest.

documentation for
public instance method resources(*entities, &block)
in ActionController::Resources in lib\action_controller\resources.rb
has more information