A photograph is an image produced by the action of light on a sensitive surface — chemical (silver halide on film or paper) or electronic (a sensor recording exposure values) — and reproduced as a print or screen image.
In formal description a photograph is treated like any other picture: it has framing, composition, palette, contrast, depth. The differences are in how those qualities are produced — through lens choice, exposure, and the mechanical capture of a particular moment — rather than through the placement of marks. Description distinguishes the photographic qualities (depth of field, grain or noise, tonal curve, the trace of a real-world referent) from the pictorial qualities a photograph shares with painting. A photograph used inside a collage, painting, or zine layout brings its own surface-character with it: the look of having been recorded rather than drawn.