A software module based on Microsoft's Component Object Model (COM) architecture. It enables a program to add functionality by calling ready-made components that blend in and appear as normal parts of the program. They are typically used to add user interface functions, such as 3D toolbars, a notepad, calculator or even a spreadsheet.
ActiveX controls can be linked to a Web page and downloaded by a compliant Web browser. Such controls turn Web pages into software as if the program were launched from a server. Like any executable program running in the computer, ActiveX controls can perform any operation on your data. This is why the default configuration in most Web browsers is to prompt the user if an ActiveX control is being requested so the user can decide to download it or not (not always an easy decision).
Originally OLE Controls
ActiveX controls were originally called "OLE controls" and used an .OCX file extension. They were Microsoft's second-generation component architecture (Visual Basic Controls (VBXs) were the first). OLE controls were renamed ActiveX and continued to use the .OCX name. See ActiveX filtering
, COM automation
ActiveX controls can be stored locally or remotely, but they are run locally.