Explain the difference between synchronous and asynchronous programming in Node.js.

Synchronous programming blocks the execution of code until a task is completed, while asynchronous programming allows other operations to run without waiting. Node.js uses asynchronous programming to handle I/O operations efficiently. For example:

const fs = require('fs');

// Synchronous read
const dataSync = fs.readFileSync('file.txt', 'utf8');
console.log(dataSync); // Blocks until the file is read

// Asynchronous read
fs.readFile('file.txt', 'utf8', (err, data) => {
  if (err) throw err;
  console.log(data); // Executes once the file is read, without blocking
});