What does these style do in html?

Question

position:
opacity:
icon:
background-position:
background-size:

Answer 1

You can see these links:
https://developer.mozilla.org/en/docs/Web/CSS/position
position - CSS | MDN
https://developer.mozilla.org/en-US/docs/Web/CSS/opacity
opacity - CSS | MDN
https://developer.mozilla.org/en-US/docs/Web/CSS/background-position
background-position - CSS | MDN
https://developer.mozilla.org/en-US/docs/Web/CSS/background-size
background-size - CSS | MDN
https://www.w3schools.com/cssref/css3_pr_icon.asp
Icon - W3Schools

Answer 2

many things

Answer 3

cool