Update site code with dynamic webpage creation

I will simplify the problem.

The basic html template of the site is like:
Header Section
Content 1 Section
Content 2 Section
Content 3 Section
Footer

If page 1 is called then show Header, Content 1, Footer
If page 2 is called then show Header, Content 2, Footer
If page 3 is called then show Header, Content 2, Content 3, Footer

One idea is to have header.html, content1.html, content2.html, content3.html , footer.html and
create page1.html, page2.html, page3.html

How could you update the...

Update site code with dynamic webpage creation WordPress ...