Why the same files are copied to /Approot and /Siteroot in Windows Azure WebRole?

Question

I found that approot and sitesroot are used for:

\Approot - The customer’s code, aspx pages, DLLs, etc. \Sitesroot\ – This is the folder where the full IIS site is run from. When the role is deployed, the files from \Approot are copied to this \Sitesroot folder and then IIS will be configured to run the site from \Sitesroot. Any temporary test changes to the role (web.config changes, new DLLs, etc) should be placed here.

I wonder why there are two sparate folders as they contain the same files?

Answer 1

• AppRoot is used at role startup and shoud contain one derived class from RoleEntryPoint. This content is from web role configured site and is used by WaIISHost worker process.
• SiteRoot contains web sites from node Sites in the .csdef file and are configured in IIS.