The Temporal Dead Zone (TDZ) is a concept in JavaScript that refers to a specific period during the execution of a program where a variable exists but cannot be accessed. This period occurs between the start of a scope (function or block) and the point where the variable is declared using the `let` or `const` keywords. The TDZ prevents developers from accessing variables before they are initialized, helping to catch potential issues related to variable hoisting and ensuring better code reliability. Understanding the Temporal Dead Zone: Let's look at an example to understand the Temporal Dead Zone: 

console.log(x); // Output: ReferenceError: Cannot access 'x' before initialization
let x = 10;
In this example, we are trying to access the variable `x` before it is declared and initialized. The code throws a `ReferenceError` during runtime because `x` is in the Temporal Dead Zone at the time of the `console.log` statement. Temporal Dead Zone and `let` and `const` Declarations: Variables declared using `let` and `const` are hoisted to the top of their scope. However, unlike variables declared with `var`, they are not initialized with the value `undefined` during the hoisting process. Instead, they remain in the Temporal Dead Zone until the point of declaration. 

function example() {
  console.log(y); // Output: ReferenceError: Cannot access 'y' before initialization
  let y = 5;
}
example();
In this example, the variable `y` is hoisted to the top of the `example` function, but it is not yet initialized. Therefore, trying to access `y` before its declaration results in a `ReferenceError`. Using `var` vs. `let` in Relation to TDZ: The Temporal Dead Zone is specific to variables declared with `let` and `const`, and it does not apply to variables declared using `var`. When you declare a variable with `var`, it is hoisted to the top of its scope and initialized with the value `undefined`. This behavior can lead to unexpected results if not carefully managed. 

console.log(z); // Output: undefined
var z = 3;
In this example, the variable `z` is hoisted and initialized to `undefined`, which is why the `console.log` statement does not throw an error. The variable `z` is accessible throughout the entire scope, not subject to the Temporal Dead Zone. Conclusion: The Temporal Dead Zone is an important concept in JavaScript that helps to identify and prevent accessing variables before their declaration. It occurs during the period between the start of a scope and the point of declaration for variables declared using `let` and `const`. Understanding the Temporal Dead Zone can lead to writing more reliable and predictable JavaScript code.