Photography is the technique, art and practice of making better images by recording light or other electromagnetic radiation, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. A photographer is a person who clicks photographs. A photographer is normally to click photographs to earn some money, by salary or through the display, sale or use of those photographs. A photographer may take photographs for happiness and to record an event, emotion, place, as a person without a economic motivation. Photographer who generate moving rather than still pictures are often called cinematographers, videographers or camera operators, depending on the trading context. Photographers are also categorized based on the subjects they photograph. Some photographers explore subjects typical of paintings such as landscape, still life, and portraiture. Other photographers specialize in subjects unique to photography, including street photography, documentary photography, fashion photography, wedding photography, and commercial photography.