ActionView::Helpers::AssetUrlHelper

This module provides methods for generating asset paths and urls.

image_path("rails.png")
# => "/assets/rails.png"

image_url("rails.png")
# => "http://www.example.com/assets/rails.png"

Using asset hosts

By default, Rails links to these assets on the current host in the public folder, but you can direct Rails to link to assets from a dedicated asset server by setting ActionController::Base.asset_host in the application configuration, typically in config/environments/production.rb. For example, you'd define assets.example.com to be your asset host this way, inside the configure block of your environment-specific configuration files or config/app