ActiveX is a technology that allows COM components, especially controls, to be more compact and efficient. This is especially necessary for controls that are intended for Intranet applications that need to be downloaded by a client before they are used. 

ActiveX controls are visual controls that run only as in-process servers, and can be plugged into an ActiveX control container application. They are not complete applications in themselves, but can be thought of as prefabricated OLE controls that are reusable in various applications. ActiveX controls have a visible user interface, and rely on predefined interfaces to negotiate I/O and display issues with their host containers. 

ActiveX controls make use of Automation to expose their properties, methods, and events. Features of ActiveX controls include the ability to fire events, bind to data sources, and support licensing. 

One use of ActiveX controls is on a Web site as interactive objects in a Web page. As such, ActiveX is a standard that targets interactive content for the World Wide Web, including the use of ActiveX Documents used for viewing non-HTML documents through a Web browser. For more information about ActiveX technology, see the Microsoft ActiveX Web site.