Hosting Environments and Script Engines
Scripts are often embedded in Web pages, either in an HTML page (on the client side) or in an ASP page (on the server side). In the case of a script embedded in an HTML page, the engine component that interprets and runs the script code is loaded by the Web browser, such as Internet Explorer. In the case of a script embedded in an ASP page, the engine that interprets and runs the script code is built into Internet Information Services (IIS).
Windows Script Host executes scripts that exist outside an HTML or ASP page and that stand on their own as text files.
Available Script Engines
Generally, you write scripts in either Microsoft JScript or VBScript, the two script engines that ship with Microsoft Windows 98, 2000 and Millennium Editions. You can use other script engines, such as Perl, REXX, and Python, with Windows Script Host.
For more information, see Microsoft Developer Network (MSDN) (https://msdn.microsoft.com/library/default.asp?URL=/library/en-us/dnclinic/html/vbsvjs.asp).
A stand-alone script written in JScript has the .js extension; a stand-alone script written in VBScript has the .vbs extension. These extensions are registered with Windows. When you run one of these types of files, Windows starts Windows Script Host, which invokes the associated script engine to interpret and run the file.
If you need to run another engine, that engine must be registered properly.