CSS Selectors ID and CLASS ========================== In addition to setting a style for a HTML element, CSS allows you to specify your own selectors called "id" and "class". The id Selector --------------- The id selector is used to specify a style for a single, unique element. The id selector uses the id attribute of the HTML element, and is defined with a "#". Do NOT start an ID name with a number! The style rule below will be applied to the element with id="para1": #para1 { text-align:center; color:red; } The class Selector ------------------ The class selector is used to specify a style for a group of elements. Unlike the id selector, the class selector is most often used on several elements. This allows you to set a particular style for many HTML elements with the same class. Do NOT start a class name with a number! The class selector uses the HTML class attribute, and is defined with a "." In the example below, all HTML elements with class="center" will be center-aligned: .center {text-align:center;} You can also specify that only specific HTML elements should be affected by a class. In the example below, all p elements with class="center" will be center-aligned: p.center {text-align:center;}