What is callback function . bhaiya i think these videso are not in a systematic way

#1

what is callback function . bhaiya i think these videso are not in a systematic way lot of things in these section does not describe anywhere

#2

You can read this famous article about callbacks here https://codeburst.io/javascript-what-the-heck-is-a-callback-aba4da2deced
It is very nicely described here.