How can you optimize an article for online media without using HTML code?

Question

Search Engine Optimization

My teacher in the discipline "Website promotion" is sure that in order to promote the materials of Internet portals, it is not necessary to enter data about the article into the page code in order to adapt it for search engines. And you can only change the text: use keywords for frequent queries, add descriptions of images, highlight certain words in bold, often divide the text into paragraphs, and so on. Are these the right means to optimize? And what other tools exist for search engine optimization of articles?
Thanks in advance for your answers.

Answer 1

Nothing without HTML. Description of images, text highlighting, semantics, etc. are all HTML.
Keys in the text, by the way, are not so important. More important is optimization for mobile devices, unique content (including images), competent semantic layout.
Also, search engines take into account the number of characters in the text and how much your material is "rummaged" in the same social networks.