Lens compatibility refers to the ability of a camera body to work with specific lenses. Different camera brands and models have unique mounts, which are the physical connections between the camera and the lens. For example, a lens designed for a Canon camera may not fit a Nikon camera due to differing mount designs. When considering lens compatibility, it's essential to check both the mount type and the lens's specifications. Some lenses are designed for full-frame cameras, while others are made for crop-sensor models. Additionally, adapters can sometimes allow lenses from one brand to be used on another, but they may affect performance and functionality.