The positioning related properties in CSS are:
Relative positioning changes the position of the HTML element relative to where it normally appears. So "left:20" adds 20 pixels to the element's LEFT position.
An element with position: absolute is positioned at the specified coordinates relative to your screen top-left corner.
Fixed positioning allows you to fix the position of an element to a particular spot on the page, regardless of scrolling. Specified coordinates will be relative to the browser window.