CSS Position description

Absolute	Generates an absolutely positioned element, selecting the first position not equal to the static location of the first parent element to locate. The position of the element is defined by the "left", "Top", "right" and "bottom" attributes.
Fixed	Generates an absolutely positioned element that is positioned relative to the browser window. The position of the element is defined by the "left", "Top", "right" and "bottom" attributes.
Relative	Creates a relative positioned element, positioned relative to its normal position. Therefore, "left:20" adds 20 pixels to the left position of the element.
Static	The default value. No positioning, elements appear in the normal stream (ignoring top, bottom, left, right, or z-index declarations).
Inherit	Specifies that the value of the position property should be inherited from the parent element.

CSS Position description