// var is a function scope *** if(true){ var varVariable = 'This is var'; var varVariable = 'This is var again'; } console.log(varVariable); // This is var again // let is a block scope *** if(true){ let letVariable = 'This is let'; let letVariable = 'This is let again'; // let variable can't re-define but we can re-assign value console.log(letVariable); // let letVariable = 'This is let again';^SyntaxError: Identifier 'letVariable' has already been declared } console.log(letVariable); //ReferenceError: letVariable is not defined // const variable can't re-define and re-assign value // const is a block scope *** if(true){ const constVarible = { name: 'JavaScript', age: '25 years', }; constVarible.name = 'JS'; console.log(constVarible) // {name: 'JS',age: '25 years'} <= we can update const variable declared object }