Introduction

The differences between Site Pages and Application Pages in sharepoint2007 and 2010 are as follows:

1. Site pages or content pages can contain one or more webpart zones and each zone can contain one or more webparts where as Application pages cannot contain webpart zones hence cannot have any web parts.
2. Site pages are confined only to a site collection where as Application pages are shared by all sites.
3. Site pages can be customized where as application pages cannot be customized
4. Example of a site page is contact us page that you can use to show the contact details of an organization in a page.
   A site page can be created by:
   Select Site Actions -> More Options
   Select "Page" category and choose page as the option and click create and save.
   The application pages are located under the C:\Program Files\Common Files\Microsoft shared\Web Server Extensions\12\Template\ControlTemplates folder.
   The folder named 12 here is called a SharePoint hive for SharePoint 2007 and for 2010 it is the folder named 14
5. When a SharePoint web application is created a virtual directory called _layouts which is mapped to the layouts folder is created in the corresponding IIS website.
   Custom application pages must be created either in the layouts folder or in a subfolder in it.
6. Site pages can use code behind filed but application pages cannot use code behind files in Sharepoint2007 but can be used in Sharepoint2010
   Application Pages use a master page called Application. master in 2007 in 2010 both Site pages and application pages use Default. master.

These are the some differences between sitepages and application pages in sharepoint. I will come back with another article, till then

Happy coding.....