What is the call stack in JavaScript?

// Example of a call stack in action
        function firstFunction() {
            console.log("First function");
            secondFunction();
        }

        function secondFunction() {
            console.log("Second function");
            thirdFunction();
        }

        function thirdFunction() {
            console.log("Third function");
        }

        firstFunction();
        // Output:
        // First function
        // Second function
        // Third function