Definition - What does ActiveX mean?
ActiveX is a framework for defining reusable software components (also known as ActiveX controls) in a programming-language independent way. Because ActiveX encapsulates specific functionality as ActiveX controls, it can be seamlessly incorporated into many software applications. The Internet Explorer Web browser allows for ActiveX controls to be embedded into Web pages. ActiveX controls officially run only in the Internet Explorer browser running on a Windows operating system.
Techopedia explains ActiveX
On the Internet, ActiveX controls have extended the capability to introduce lively and elegant content, multimedia effects, interactive features to Web pages and software applications. The extension provided by the ActiveX technology is limitless – ActiveX controls have full access to the entire PC and all services of the Windows operating system. With this power comes a responsibility to provide security to the user. Microsoft has countered the potential risk of malware by developing a registration system that allows the browser to identify and authenticate an ActiveX control before downloading it. In addition, it is recommended that users set the default browser configuration such that they are prompted to approve any request for the download and execution of ActiveX controls.
ActiveX controls are embedded in container applications. Many third-party vendors have adopted ActiveX as an important architecture for developing programmable software components for use in a variety of different containers, ranging from software development tools to end-user productivity tools. For a control to operate well in a variety of containers, it must be able to assume some minimum level of functionality that it can rely on in all containers. These details are part of the ActiveX guidelines.
While similar to Java applets, ActiveX controls differ by two main attributes. Java applets do not have the same unlimited access to the Windows operating system as ActiveX controls do. The applets, however, are more versatile in the sense that they are truly multiplatform, while ActiveX controls are limited to the Windows operating system.