Callback hell is a popular JavaScript anti-pattern used when functions are deeply nested to handle asynchronous operations. Such deep nesting makes code hard to read, understand, and maintain.

What is Callback Hell?
Imagine you have to execute a few asynchronous tasks which depend on the result of the previous one. A traditional callback approach leads you to a pyramid-shaped nesting of callbacks, which closely looks like a pyramid of doom.

Now, observe the code, how the lines get indented as more and more callbacks are nested. This, in turn, causes severe problems as mentioned below
Readability : The code becomes very difficult to understand and maintain.
Error Handling: The error handling mechanisms become messy and error prone.
Testing: Testing deeply nested callbacks is hard work.
Escape from Callback Hell

Fortunately, there exist several successful strategies that let you escape from callback hell:
Promises are better for managing asynchronous operations and provide a more structured interface. They represent the successful or failed completion of an asynchronous operation along with its final value.

Async/await is syntactic sugar over Promises which allows us to write an asynchronous code that looks synchronous in appearance.

Generator-based solutions are far more flexible for controlling the flow of asynchronous operations, particularly in complex scenarios.
You can use these techniques to create cleaner, more maintainable, and easier-to-understand asynchronous code in JavaScript.