A photographic process invented in 1839 by Louis-Jacques-Mandé Daguerre (1787-1851). The first practical photograph, a daguerreotype was a positive print made on a light-sensitized copper plate. By 1860, new, less expensive processes had almost completely replaced it. Pronunciation here. Web resource here. Videos here and here.
Daguerreotype of Louis Daguerre by Jean-Baptiste Sabatier-Blot. 1844.