E(h,f), what is the entirety of h and f?

[pouramini]

The books says:

While E(h, f) is based on the entirety of h and f , it is almost universally defined based on the errors on individual input points x.

Maybe it is a mathematics question, but I don't get "the entirety of h and
f". aren't they a collection of points? then I expect they are defined according to the points... an example how they could be defined otherwise would be helpful!