Margin

The   property is used in CSS and certain HTML elements. It sets the margin for all four sides of the object. It is a shorthand to avoid setting each side separately with the other margin properties:,  ,   and.

Values
div { width:50%; margin:0 auto; } centers the  container horizontally.
 * - Specifies a fixed width. Negative values are allowed. Ex.,  , etc.
 * - A  relative to the width of the containing block. Negative values are allowed.
 * -  is replaced by some suitable value, e.g. it can be used for the centering of blocks.
 * One single value applies to all four sides.
 * Two values apply first to top and bottom, the second one to left and right.
 * Three values apply first to top, second to left and right and third to bottom.
 * Four values apply to top, right, bottom and left in that order.

HTML example:

 1st heading content.

CSS example:

h1 { margin:5px 10px 5px 10px; }