The Position Property
The position property determines whether elements are "normal" elements, or whether they are subject to relative, absolute, or fixed positioning.
Elements that don't use any positioning methods are called static. This is the normal case. The values absolute and fixed imply that the element must be a block. The value of the display property is ignored in this case. Elements that are not static make use of the four positioning properties: top, right, bottom, and left.
These properties determine the position of a positioned element by setting the distance from the edge of a so-called containing block, which is explained in the next section. The meaning changes slightly with the type of positioning and will be explained in following sections.