Question

Why is the STL considered a library, but the JCF a framework? What exactly is it in their respective designs that causes/justifies this distinction? Can you give a code example that illustrates this?

Answer 1

Definition by Martin Fowler:

A library is essentially a set of functions that you can call, these
days usually organized into classes. Each call does some work and
returns control to the client.

A framework embodies some abstract design, with more behavior built
in. In order to use it you need to insert your behavior into various
places in the framework either by subclassing or by plugging in your
own classes. The framework’s code then calls your code at these
points.

More discussion can you find here:
What is the difference between a framework and a library?