What does a digital camera do?

Digital Cameras mainly take photos, but they can have extra features that enable it to do more, like record Video, take photos when a certain amount of movement is detected. Most Digital Cameras use SD or SDHC cards and can differ in performance, like Mega Pixels how sharp a photo is when taken, Zoom how close you can get onto an object, Speed how fast Focusing is in Automatic, Settings what you can Adjust in the Camera to change the brightness, White Balance and looks (Color, B&W).