What is the difference between "undefined" and "null" in JavaScript?

In JavaScript, "undefined" and "null" are both primitive values, but they have different meanings.

"Undefined" means a variable has been declared but has not been assigned a value. It is a type representing the absence of a value.

"Null", on the other hand, is an intentional absence of any value. It is an assignment value that indicates a variable has no value.

It's important to note that typeof null is "object" while typeof undefined is "undefined".

Understanding the difference between "undefined" and "null" in JavaScript is crucial for properly handling variable assignments and checking for the existence of values.