This leaves room for growth, we can have other attribute files as part of a website, and it makes for easy compatibility with the Frontier site framework. The file has a .html extension so that BBEdit knows to use color coding as you're editing the file. When you render a page, Frontier looks for the template file in the same folder as the file. If it doesn't find it there, it pops out a level and looks there. It keeps popping out until it reaches the desktop.
Some commands key off the location of the template file.
When you choose the Backup Site command, it copies all the files and sub-folders of the folder that contains the template file. Same with the Render Whole Site command. Converting an existing site Look for the common structure in all the pages, and put that into the template, and delete it from each of the files. This can be a tedious manual job, but there's no way to avoid it. Once you've made the conversion, changing the look of your site will be automatic.