Stylesheet rules define presentational aspects of the following parts of a document:

Text

em {font-size:24pt;color:red;background-color:white}

Words

em {letter-spacing:10pt}

Pseudo-elements

em:first-letter {font-size:48pt}

Area of Elements

p {width:200px;height:100px}

Space around Elements

p {margin:20px; padding:20px; border:solid red 3px}

Positioning of Elements

p {position:relative;left:100px;top:50px}

We will talk about each in more detail later