Lens adapters are accessories that allow photographers to use lenses from one camera system on a different camera body. They bridge the gap between different brands or types of cameras, enabling users to take advantage of various lens options without needing to invest in new equipment. These adapters can vary in design, with some providing additional features like autofocus or image stabilization. However, it's important to note that using a lens adapter may affect the lens's performance, such as altering the focal length or limiting certain functionalities. Popular examples include adapters for Canon lenses on Nikon bodies or vice versa.