Hello readers 👋, welcome to the 14th blog in this JavaScript series! Today, let’s talk about something that’s at the heart of asynchronous JavaScript: callback functions . If you’ve ever worked with async code, you’ve probably used callbacks, maybe without even realizing it. Callbacks can seem a bit abstract at first, but once you understand why they exist and how they work, they become a powerful tool in your coding toolkit. Let’s break it down step by step. What is a callback function? In JavaScript, a callback function is simply a function that is passed as an argument to another function and is executed after some operation has been completed. In other words, it’s a function that “calls back” when something is done. Here’s a basic example: function greet ( name , callback ) { console . log ( `Hello, ${ name } !` ); callback (); } function sayGoodbye () { console . log ( " Goodbye!…