 Hi, in this tutorial we're going to talk about var, let and const in JavaScript language version ECMAScript 6. So if you want to declare a variable by using var keyword, then that variable will be treated as a variable in global scope. So it doesn't matter where you actually want to declare that variable, that variable is going to be visible everywhere inside your program. So if you have for example a function and you want to create a new variable, that new variable declared inside this function is going to have the same global scope as this variable here. So any variable declared by using var keyword is going to be visible. This value is going to be visible inside your program. But if you want to use keyword let to define your variable, then your variable is going to be visible just inside this code block or between these two curly braces. If you want to use this variable outside of this block, this variable is going to be undefined. So this variable here is going to be undefined, but variable declared with keyword var is going to be visible so you can use it further in your program. And finally, if you want to declare a constant value, you're gonna use keyword const and it is almost the same as working with keyword let, but you just can change the value of your constant so you can say that your constant now has some new value. Also constants are visible just inside this block because outside of these curly braces, this constant is going to be undefined. That's all in this tutorial. Thanks for watching. Don't forget to subscribe to my channel. Bye.