OCX (Object Control eXtension) is a software component that allows developers to create reusable and interactive controls for Windows-based applications. In the context of IP cameras, OCX control refers to a software library that provides a set of pre-built functions and tools for interacting with IP cameras. These controls enable developers to create custom applications that can access and control IP camera features, such as video streaming, pan-tilt-zoom (PTZ) control, and motion detection.