Definition - What does Activex Control mean?
An ActiveX control is a small program that is used to share information between applications. An ActiveX control can enhance Internet browsing experience by allowing animation and is often compared to Java applets. Microsoft developed the concept in the mid 1990s.
While technically still around technology is no longer commonly used in modern web development.
Techopedia explains Activex Control
ActiveX is (was) an outgrowth of two other Microsoft technologies, object linking and embedding and the component object model. ActiveX controls refer to a specific way of implementing those technologies.
A limitation of the ActiveX control is that it can only run under Windows. ActiveX controls can also expose a system to viruses and malware because they create an opening that can allow these malicious programs to be installed.