Margins settings allow you to manipulate the margins of text or images. The MARGIN properties can be adjusted so that elements can be closer or father apart.
What are MARGINS ?
Margins are the space between the text or image's bounding box and the bounding box of adjacent text or images. Each side of the Margin (left, right, top, bottom) can be changed the same way. To change the values, pick a radio button, then adjust it's numeric value. If Auto is chosen, then the value will be left up to the browser.

Width: Refers to the value of the width of the element. Specify either a pixel length, a percentage, or auto to let the browser adjust the value.
Height: Refers to the value of the height of the element. Specify either a pixel length or a percentage.
Other Properties: