Empty string

An empty string is a string that doesn't have any letters or numbers in it at all. It's like when you write a letter, but you don't write anything inside the envelope. It's still a letter, but there's nothing to read inside. Same with an empty string - it's still a string, but there's nothing to read inside of it. Think of it like an invisible string - you can't see the string itself, but you know it's there because you can see its effects, like when you tie your shoes. So an empty string exists, even though you can't see any letters or numbers in it.