How to explain callbacks in plain english? How are they different from calling one function from another function?

Question

How to explain callbacks in plain English? How are they different from calling one function from another function taking some context from the calling function? How can thei

Answer 1

A metaphorical explanation:

I have a parcel I want delivered to a friend, and I also want to know when my friend receives it.

So I take the parcel to the post office and ask them to deliver it. If I want to know when my friend receives the parcel, I have two options:

(a) I can wait at the post office until it is delivered.

(b) I will get an email when it is delivered.

Option (b) is analogous to a callback.