We like footer areas that contain more information than just a copyright statement. Typically we will add room for main navigation links, contact information, social media icons, your copyright statement, and other blocks for information you consider important enough to show on every page.
You will edit the footer content on the .dwt template pages if you are using Expression Web (or Dreamweaver). Once you have changed content, you can copy and paste it into your other .dwt template pages.
You can then highlight the footer tag on another .dwt template page, and Control + V to paste over the old code with your new changes.