phplib template class help

Can someone please explain how this works, I don't necessarily need help with the functions just the details, specifics of how I should go about implementing it,the order in which files are parsed,etc. For example, I have a site I want to do (shopping cart), I want one main template, with several smaller ones included at my whim. What I don't understand is the main concepts, how it functions. I think I could use it a lot better if I understood it. I've read and read until I can't read anymore, the docs are kind of cryptic and only good for function references. -Mark