understanding templates

Hi, I’m trying to learn WP with a view to migrating from Dreamweaver and I’m stuck on templates (well, stuck on lots of things actually but one at a time!)
In Dreamweaver, I create a dummy page that has editable and non editable areas and save this to a templates folder as a .dwt file. I can then open this template, drop images into the relevant editable sections and text into others etc. for example I have a template called ‘models.dwt’. I can put in an image of a Diamond Kite, add text about diamond kites into the relevant editable sections and save this to my site as ‘diamond’html’ and the page will be added to my site.
Am I correct in assuming that templates doesn’t have the same meaning in WP?
If this is correct, what is the equivalent in WP?
I’ve can’t find anything that looks like a ‘save as’ button on WP so maybe I am completely on the wrong track. What am I missing?
Thanks