what is the function of superscripted tag?

Answer 1

The tag <sup> make the text supercribe, for example:

X²
Is the same as
X²

Check this lesson about formating text:
https://www.sololearn.com/learn/HTML/1026/

You can check this example of W3SCHOOL :
https://www.w3schools.com/tags/tryit.asp?filename=tryhtml_sup