1<!DOCTYPE html>
2<html>
3<head>
4<style>
5.classname {
6 background-color: green;
7 color: white;
8}
9#idname {
10 background-color: pink;
11 color: white;
12}
13</style>
14</head>
15<body>
16<div class="classname">I am green colour<div>
17<div id="idname">I am pink colour</div>
18</body>
19</html>
20
1# in CSS means your looking at an ID so
2<div class="ExampleClass" id="ExampleID"></div>
3
4#ExampleID would reference the ID
5.ExampleClass would reference the class