var firstInstructor = "Colt";
firstInstructor = "Elie"; // no problem here
const anotherInstructor = "Tim";
anotherInstructor = "Elie"; // TypeError
const anotherInstructor = "Elie"; // SyntaxError
Can NEVER redeclare
const numbers = [1,2,3,4];
numbers.push(10); // 5
numbers; // [1,2,3,4,5]
numbers = "no!"; // TypeError
Can mutate if it is an object, but not declare again