Explain the concept of function overloading and its application in programming.

Function overloading is the ability in some programming languages to create multiple functions with the same name but different parameters (by number or type). This allows using one name for different behavior variants of a function depending on the arguments passed.

In JavaScript (and Node.js), there is no direct support for function overloading, but similar behavior can be implemented by checking the types and number of arguments inside the function.

Example of simulating overloading in Node.js:

function greet(name, age) {
  if (typeof age === 'undefined') {
    console.log(`Hello, ${name}!`);
  } else {
    console.log(`Hello, ${name}! You are ${age} years old.`);
  }
}

greet('Anya');       // Hello, Anya!
greet('Ivan', 30); // Hello, Ivan! You are 30 years old.

Overloading is useful for creating convenient and understandable function interfaces, allowing to handle different call scenarios with one name.