A camera is an optical device that captures still photographs or video images. It works by focusing light through a lens onto a photosensitive surface, such as film or an electronic sensor, which records the image. Cameras come in a wide range of sizes and types, from small point-and-shoot models to professional-grade digital single-lens reflex (DSLR) cameras. They may also have various features and settings, such as autofocus, flash, image stabilization, and manual controls for exposure and focus. Cameras are used in a variety of applications, including personal photography, journalism, filmmaking, surveillance, scientific research, and many others.