What is "silver halide"

A silver halide (or silver salt) is one of the compounds which are formed between silver and one of the halogens – silver bromide (AgBr), chloride (AgCl), iodide (AgI), and three forms of silver fluoride. As a group, they are often referred to as the silver halides, and are often given the pseudo-chemical notation AgX. Although most silver halides involve silver atoms with oxidation states of +1 (Ag), silver halides in which the silver atoms have oxidation states of +2 (Ag) are known, of which silver(II) fluoride is the only known stable one.

The light-sensitive chemicals used in photographic film and paper are silver halides.