ActiveX is a software framework created by Microsoft that allows interactive content to run on web pages. It enables developers to create applications that can be embedded in web browsers, providing features like multimedia playback, data visualization, and enhanced user interfaces. ActiveX controls are small programs that can be downloaded and executed within a browser, but they can also pose security risks. Because they have access to the user's system, malicious ActiveX controls can potentially harm computers or steal information. As a result, many modern browsers have limited or discontinued support for ActiveX technology.