Page 14 of Fundamentals of Computer Graphics states that if we have a function like this:
...the set that comes before the arrow is called the domain of the function, and the set on the right-hand side is called the target.
...The point f(a) is called the image of a, and the image of a set A (a subset of the domain) is the subset of the target that contains the images of all points in A. The image of the whole domain is called the range of the function.
Then what exactly is the difference between the range of a function and the target of a function?