what is the function of ' display: fixed;' on css code example

Example: what are the types of positioning in css

The types of positioning in CSS are-
1)static: this is the default value.
2)sticky: the element is positioned based on the user's scroll position.
3)fixed: the element is positioned related to the browser window.
4)relative: the element is positioned relative to its normal position.
5)absolute: the element is positioned absolutely to its first positioned parent.