Image is a related term of preimage. Preimage is a derived term of image.
In context terms the difference between preimage and image is that preimage is the set containing exactly every member of the domain of a function such that the member is mapped by the function onto an element of a given subset of the codomain of the function formally, of a subset b'' of the codomain ''y'' under a function ƒ, the subset of the domain ''x defined by while image is the subset of a codomain comprising those elements that are images of something.
As nouns the difference between preimage and image is that preimage is the set containing exactly every member of the domain of a function such that the member is mapped by the function onto an element of a given subset of the codomain of the function formally, of a subset b'' of the codomain ''y'' under a function ƒ, the subset of the domain ''x defined by while image is an optical or other representation of a real object; a graphic; a picture.