Major forms of photography include single photos, picture groups, sequences, series, and photo essays. Photo essays allow photographers to explore stories in more depth than single photos by depicting concepts or themes over longer periods of time with multiple related photos and a personal viewpoint. Effective picture stories include 4+ photos accompanied by text to tell about a subject, with all photos relating to each other and the broader story. Photographers are advised to thoroughly research and document subjects to effectively capture and sequence photos that clearly and cohesively tell the story.