1. Callbacks:
Callbacks are a fundamental concept in asynchronous programming in Node.js. They are functions that are passed as arguments to other functions and are executed after the completion of an asynchronous operation.
In the example above, the readFile function takes a callback function as its third parameter, which gets executed once the file is read.
2. Promises:
Promises provide a cleaner way to handle asynchronous operations compared to callbacks. They represent the eventual completion or failure of an asynchronous operation, and you can chain multiple asynchronous operations using .then().
Promises make error handling more straightforward with the use of .catch().
3. async/await:
Introduced in ECMAScript 2017 (ES8), async/await is a syntax for handling asynchronous operations that makes the code look more synchronous and readable. async is used to define a function that returns a Promise, and await is used to wait for the resolution of a Promise inside that function.
async/await simplifies the syntax and makes the code more readable, especially when dealing with multiple asynchronous operations.
4. Handling Multiple Promises Concurrently:
Promise.all allows you to execute multiple asynchronous operations concurrently and wait for all of them to complete.
Understanding these concepts is crucial for effective asynchronous programming in Node.js. They provide flexibility in managing non-blocking operations, which is a key feature of Node.js, allowing it to handle many connections simultaneously.
