Q:

HTML templating like PHP templating

I know things like these have been asked and answered several times before, is it just that I can't grasp the idea easily or too hard to accept that things are really like this and that.
I know that HTML is used for Front-End where the tedious work is done in the Client, and PHP is working behind the scenes (Server-Side). With so many regulations, instruction, standards, so on and so forth.. I believed I have already confused myself with these stuffs, making things (new and old) hard for me to chew and understand especially when it comes to their best uses...
Anyway, I have created a web application based on the concept of MVC tho I didn't used the strong fundamentals of the topic nor a framework, I separated the Logic, Rules and Design concerns by my own.
Unfortunately, I wound up with some issues similar to which is the right way to do the things, how this should be implemented, etc...
I end up needing to template the HTML, however, since I've used HTML as HTML itself, I end up updating/editing each and every affected file (for. eg. a web page header), unlike when I used PHP before, literally a file with a .php extension, where I can fully utilize templating, however, i read somewhere that it is not a good practice because it breaks the HTML.. so which one should I follow and how can I solve my problem, should I move to .php and then create a template page, or is there a way I could do such with HTML? if there is any, how can it be done?
Please for the meantime, don't point me to frameworks available, I want to understand basic things first before studying frameworks...
Anyone, please...
Edit...
so this is just fine and that it doesn't have any drawbacks...
main.php 
 <?php php stuffs ?>
 <html>
 <body>
  HTML stuffs and some <?php php stuffs ?>
 </body>
 </html>

A:

HTML has no templating capability.
It has frames and iframes, but they come with significant drawbacks and only provide include functionality.
You should use a proper templating language. This can run on the client, server or build system. 
I'd recommend against running it on the client. It adds an unnecessary dependency that your visitors (including search engine indexers) have to fulfil.  
PHP will do the job (it straddles the border of being a programming language and a templating language). My personal preference is for Template-Toolkit.
TT can run in your build system via the ttree utility, or you can run it on your server. There is a tutorial covering how to build websites using it.
If, and when, you move to building websites with more demanding server side requirements, then you can continue to use TT as it is supported but most of the web frameworks in Perl land (e.g. the dancer module for TT and the catalyst module for TT. Note that those links go to the hardcode documentation for the modules, and if you plan to use one of the frameworks you should start with a higher level tutorial)

