Photography describes a technology that records lasting images from real life by utilizing light or other electromagnetic radiation, either electronically or through an image sensor or chemically using a light-sensitive material. A camera is the tool used to capture and focus light reflected from objects into a replicate image on the light-sensitive surface inside the device (camera) during a timed period called "exposure". The result is an invisible image which is later chemically brought forth into a visible image or recorded on a digital card inserted in camera. Photography is often used to document a period, mood or moment. The immediacy of the camera's ability to capture images gives cause to the role of photography in art.