Using VBScript on the server in an ASP page really isn't very different from using VB in applications, or VBA in Microsoft Office, or VBScript on ordinary Web pages as a client-side technology. Nearly all VBScript commands are available for use with ASP except for those that interact with the user. Imagine the dilemma caused by a VBScript command to display a message box on the server. This would require someone to notice and dismiss it on the server before the system could proceed. Instead, the scripting language must interact with the user through HTML and the http protocol.
Scripting languages are great for creating applications quickly.
Most of the functionality you can build into an ASP page comes from objects on the server. IIS 4.0 comes with six important built-in objects, as well as a number of installable objects. You can create your own objects by building new server-side ActiveX components. You can get FORM data, read cookies, and so forth. Response object - sends information to the user.