WordPress functions can reduce the number of HTML elements, thus improving web efficiency. Changing HTML in templates is easy, as one template is responsible for a lot of pages. But changing content-based HTML is difficult. There are individual things that may need to be updated manually one post a time because it comes in hundreds to thousands. Even if required, the less HTML in the post, the better.
Strategies for adapting content
These are the tools offered by WordPress , amongst other useful tools :
The post will briefly explain how the two work. Also real word examples to show what you can do with them.