All elements (tags) in html have four core elements:

  1. ID is the SSN or - Each Student Unique Student Id
  2. Class is the Class - CIM289 many Students
  3. Style local override CSS style information
  4. title tool tips hover around the link below for some help

W3C Validator

Note with css with start a selector with...

. or period for specifying a class

# for specifying a ID

Valid XHTML 1.0 transitional Valid CSS!