It might be the path or the current page or values in the querystring.
Here is a simple reference to different uri based info available to you out of the box.
SAMPLE URL:
http://habeeb.in/UrlTest/Default.aspx?QueryString1=1&QueryString2=2
CODE:
Response.Write( Request.Url.Host ); Response.Write( Request.Url.AbsolutePath ); Response.Write( Request.ApplicationPath ); Response.Write( Request.Url.AbsoluteUri ); Response.Write( Request.Url.PathAndQuery );
OUTPUT:
habeeb.in /UrlTest/Default.aspx /UrlTest http://habeeb.in/UrlTest/Default.aspx?QueryString1=1&QueryString2=2 /UrlTest/Default.aspx?QueryString1=1&QueryString2=2
The above sample "Request.Url" is when you use in ASP.NET Code behind.
If you use it within a class library then you will have to refer it as ""HttpContext.Current.Request.Url".