Math Help - Image set

I am not sure what an image set is. Is it the range/image of a function or the codomain, which is a superset of the range?

An image set of a mapping is the set of second terms of the pairs that make up the mapping.

The image set is the set of images of the elements in the domain. A book of mine is wrong to to say the image set and codomain are the same thing.

Originally Posted by Stuck Man

The image set is the set of images of the elements in the domain. A book of mine is wrong to to say the image set and codomain are the same thing.

Definitions can never be wrong. They may well be at odds with standard, common usage. But not wrong.