I'm new to programming and if I'm wrong please someone correct me!

I believe it's because it's being considered to be null terminated strings.
Therefore the last character of these strings are '\0', but in a empty string this would be the only character
and when we compare it with a string that isn't empty it would return true since '\0' is present in both.

But as far as I understand it isn't something that will be printed in the screen, just something that will be
considered by the machine.

I guess you're talking about Python (always state the language when the kata has more than one). We need to see your code formatted in a post marked as having spoiler content to help you. More than 1900 persons passed in Python so it's more likely your code what's wrong.