Difference between var ,let and const?

 'var' is function scoped but 'let' and 'const' are blocked scoped .

example-

//ES5

function driverLisence(passedTest){

    if(passedTest){

        var name="lokman";

        var yearOfBirth=1990;

    }

      console.log(name+"  born in " +yearOfBirth+"have successfully passed the license test");

//name and yearOfBirth will accessible within the body of the function because var is function scoped.

}

driverLisence(true);

//ES6

function driverLisence(passedTest){

    if(passedTest){

        let name="muna";

        const yearOfBirth=1995;

       

    }

     console.log(name+"  born in " +yearOfBirth+"have successfully passed the license test");

//name and yearOfBirth will not accessible outside of the if block . because they are blocked scoped. 'const' will not changed once initialized.

 }

driverLisence(true);