static - All HTML elements are positioned static by default, meaning they are positioned with the flow of the page.
relative - In order to use any other postition property different than static the parent element needs to have position: relative;, so that it's children can be positioned against it via properties top, bottom, left, right.
fixed - Element gets positioned relative to the viewport.
absolute - Element is positioned relative to the nearest positioned ancestor (anyone except static ones), else uses the document body if no other non static ancestor is available.
sticky - Element is positioned based on the user's scroll position, toggles between relative and fixed.