Photojournalism involves using photographs to tell news stories or document events. There are two main types - images that illustrate written articles, and images that tell stories on their own without words. A key skill for photojournalists is being able to quickly react to potentially newsworthy scenes. Effective photos have qualities like prominence, timeliness, action, and human interest. Captions are brief text descriptions that accompany photos and provide context, while cutlines describe photos underneath in publications. Captions should be concise yet explanatory and include who, what, when details about the photo.