This lecture delves into the concept of callbacks, explaining their synchronous and asynchronous nature. It highlights the complexities of callback hell through practical examples, demonstrating how nested callbacks can lead to confusion. The lecture also covers error handling in callbacks and sets the stage for introducing promises as a more efficient alternative in the next session.

Explain how to create a simple login function using callbacks.

What is the role of the 'setTimeout' function in asynchronous programming?

How do you pass a callback function as an argument in JavaScript?

What steps would you take to refactor callback hell into a more manageable structure?