What Does Remote Desktop ActiveX Control Mean?
The Remote Desktop ActiveX control is one of the ActiveX controls supported by Microsoft's Remote Desktop Services. Remote Desktop Services are those services supported within a Windows network that provide remote access to other desktops within the same network. This particular ActiveX control allows remote access to take place within a Web browser.
Techopedia Explains Remote Desktop ActiveX Control
To better understand the Remote Desktop ActiveX control, one has to first understand the purpose of ActiveX controls. Basically, ActiveX is an object linking and embedding (OLE) object that provides a framework upon which Web programmers can build with the assumption that this underlying framework will be supported across the Internet. This also assumes that the various users across the Internet will be using Internet Explorer. So, if a remote computer is using ActiveX, the person attempting to access this computer via Remote Desktop Services will be able to interface with this remote computer via Internet Explorer.