The difference between the words “photo(graph)” and “picture” confuses many people. A photograph (photo for short) is a subset of the category “picture.” Hence, a photo is always a picture, but a picture is not always a photo. Photos are images taken with a camera, whereas pictures can also be drawn by hand using pencil or crayon, painted, or even generated by computers using Microsoft Paint software, for example.
The word “photograph” first appeared in the English language in 1839, whereas the word “photo” didn’t come into fashion until 1860, according to Webster’s Ninth Edition dictionary. In 1839 Louis Daguerre invented the first practical process of photography, naming it after himself – the daguerreotype. It involved a sheet of silver-plated copper, polished and coated in iodine, creating a light-sensitive surface. The plate was placed in a camera and exposed for a few minutes, then bathed in a solution of silver chloride to form a lasting image that would not change if exposed to light.
Pinhole cameras date back to around 1000 A.D. They were based on an observation made around 330 B.C by Aristotle, who noted that the sun made a circular image when it shined through a square hole.