An ActiveX control is pre-coded software designed to extend the functionality of web browsers. The idea behind ActiveX controls was to design code blocks that could be plugged into web browsers and execute simple functions, such as playing multimedia or editing documents, without the need for external software or opening a new browser window.
ActiveX technology was launched by Microsoft in 1996 and was notorious for its security flaws from the beginning. Many web browsers have gradually been avoiding using the technology since 2015 and moving on to newer and more secure solutions. However, ActiveX was officially deprecated in June 2022 when Microsoft announced that Internet Explorer 11 would no longer be supporting it.