Compact digital still cameras can record sound and moving video as well as still photographs. Most 21st century cameras are digital. Digital cameras display images on a screen immediately after they are recorded, storing thousands of images on a single small memory device, recording video with sound, and deleting images to free storage space. Some can crop pictures and perform other elementary image editing. Some have a GPS receiver built in, and can produce Geo-tagged photographs.
Digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles. The Hubble Space Telescope and other astronomical devices are essentially specialized digital cameras.