What does :namespace do when invoked with use in *_web.ex?

[toraritte]

For example:

  def controller do
    quote do
      use Phoenix.Controller, namespace: RumWeb
      import Plug.Conn
      import RumWeb.Router.Helpers
      import RumWeb.Gettext
    end
  end

  def view do
    quote do
      use Phoenix.View, root: "lib/rum_web/templates",
                        namespace: RumWeb

      # Import convenience functions from controllers
      import Phoenix.Controller, only: [get_flash: 2, view_module: 1]

      # Use all HTML functionality (forms, tags, etc)
      use Phoenix.HTML

      import RumWeb.Router.Helpers
      import RumWeb.ErrorHelpers
      import RumWeb.Gettext
    end
  end

Tried to follow it but it needs more time to figure it out.

[toraritte]

From the Phoenix.Controller documentation:

Options

When used, the controller supports the following options:

• :namespace - sets the namespace to properly inflect the layout view. By default it uses the base alias in your controller name

• :log - the level to log. When false, disables controller logging