For every page, there's an entry in the pages.yml file specifying the template, module and page-variables/includes.

A basic pages.yml:

---
  (pagename):
    template: "templates/standard.html"
    pagevar:
      $include: "includes/include.html"
      var: "Variable"
    pagemod:
      (modid):
        mod: "page"
  (pagename):
    template: "templates/other.html"
    pagevar:
      title: "pnbp"
    pagemod:
      (modid):
        mod: "page"
        settings:
          location: "space"

(pagename)

This specifies the name and location of the page.

"index" is a special term used to define the home page of the website, thus creating this page in the root of the website.

template

This specifies the location of the template that is going to be used in this page.

pagevar

These are the variables that are specified in the templates to be replaced with the values specified.

Includes are specified with a '$' at the beginning of the name of the variable, followed by the the value being the location of the file to include.

pagemod

This is a specialized set of variables, pointing to a module that can create subpages.

(modid) is used for the id of the module that is being used. This may be used in different ways for different modules. For information on the use of (modid), refer to the documentation of the module being used.