MathJax

HTML is nice but hard to type math stuff like fractions and equations... how can math things be shown on a webpage? Sure people can use powerful equation editors nowadays to generate PDFs. Traditionally math text are typeset by Tex/LaTex. And with MathJax you can now turn that into webpage:

$$x = {-b \pm \sqrt{b^2-4ac} \over 2a}.$$

becomes $$x = {-b \pm \sqrt{b^2-4ac} \over 2a}.$$ Tex/LaTex however has a bit of learning curve. There are tutorials out there. But now there is WYSIWYG editor too: https://latexeditor.lagrida.com/

You an also use Jupyter Notebook to type equations in similar ways and also run Python right on it too. So if you have math things to tell, now it is easier to display your equations and data charts etc.