// Variables (let, const, var) let name = 'Node.js'; const version = 20; // Function declaration function greet(user) { return `Hello, ${user}!`; // Template literal (ES6) } // Arrow function (ES6+) const add = (a, b) => a + b; console.log(greet('Developer')); // Hello, Developer! console.log(add(5, 3)); // 8