That's a great question!
In JavaScript, undefined is a primitive value that means a variable has been declared but has not yet been assigned a value. It's essentially a placeholder indicating that "nothing has been explicitly defined here."
For example, when you wrote let message;, you declared the message variable, but you didn't give it an initial value. So, if you were to try and log message to the console right after that line, you would see undefined.
It's different from null, which is an assignment value meaning "no value" or "empty value" and must be explicitly set.
Does that help clarify what undefined means?
