Those “_path" methods are helper methods generated by your “routes.rb” file, which has nothing to do with link_to’s. When you define a named route by saying "map.”,you will get a “*_path” method points at your target. You can choose whether to use it or not in link_to tag. For more information about link_to, you can refer to
http://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#M001601
Good luck
