common header and footer for all pages in drupal7 i use different layouts for different pages for a large website, which share common header and footer. how can i create common header and footer templates and link the templates to these pages.
The most common is to structure your header and footer using the core block system. Another solution would be to place the structure in the page.tpl.php. If you have a lot of page.tpl.php files and still want to use templates, then it might be better to place the header and footer in the html.tpl.php template.

Personally I would recommend using the blocks system.