From http://www.w3schools.com (Copyright Refsnes Data)

VBScript Introduction

What You Should Already Know

Before you continue you should have a basic understanding of the following:

• HTML / XHTML

If you want to study these subjects first, find the tutorials on our Home page.

What is VBScript?

• VBScript is a scripting language
• A scripting language is a lightweight programming language
• VBScript is a light version of Microsoft's programming language Visual Basic

How Does it Work?

When a VBScript is inserted into an HTML document, the Internet browser will read the HTML and interpret the VBScript. The VBScript can be executed immediately, or at a later event.

From http://www.w3schools.com (Copyright Refsnes Data)