I am wondering if it is possible to create a 'master html' document that is inherited by all of the other pages on the site. By that I mean, a way to make any changes to index.html apply to all other pages. So that if I have to change something on index.html, it will be applies to all other pages. Then on the individual pages I can make any particular html edits I need to make. Any ideas? Thanks!
There are a couple of ways to do this
The advantage of using serverside or clientside includes is that you only need to change and upload the included file; with the templates you need to upload all of the affected files.
One handy commercial product for PHP can be found here http://www.webassist.com/dreamweaver-extensions/framework-builder/
Guidance on when to use DW Templates, Library Items and SSIs -
DWT Template Basics -
More on DWTemplates -