I am going through Category Theory for Scientists. I am on section 2.5.1 Pullbacks.
I am having trouble visualizing a pullback.
Earlier in the book the author gives a nice diagram of an example of products of sets.
There is a similar diagram for coproducts of sets.
Is there some way to draw an example of a pullback or a fiber product? Or is there some sort of example that would make pullbacks and fiber products easier to understand for someone coming from a programming background as opposed to a math background? Or am I just thinking about this completely wrong?