#blue { color: blue; } /*same as h1#blue, unique name*/

h1 { /*all element h1 --> selector*/
  font-family: courier;
  font-size: 160%;
}

.red { color: red; } /*same as p.red */

p.myborder {
  border: 1px solid powderblue;
  padding: 30px;
}

p#mymargin { /*same as #margin */
  border: 1px solid powderblue;
  margin: 10px;
}