Template overrides are, for me, the most powerful feature of Joomla. I use them a lot and they are what makes the difference between a good looking website and a great one. They can be as simple as moving the intro image above the article title to something more complex, including CSS and JavaScript changes, such as creating a photo gallery from a category of articles or creating a set of buttons to filter the content.
Read more https://magazine.joomla.org/all-issues/may-2023/template-overrides-recycle-and-reuse