ActiveX is a brand name referring to a set of Microsoft's technologies and services based on COM (Component Object Model) widely released in 1997. On the Internet, ActiveX can be used with IE versions 3 and above and with Netscape Navigator though plug-ins.
ActiveX control is a COM object, written as a DLL in a programming language like Visual Basic, that follows ActiveX standards. Once downloaded, ActiveX controls have a large degree of freedom, presenting a security risk. ActiveX controls have to be digitally signed by their creator. Major competitor to ActiveX controls are JavaBeans. Some hosts support ActiveX server components for ASP.