Security isn't just a mere name for Apple Inc. That's why it has developed a sophisticated anti-fraud technology to identify which users may not be real. At first, the idea was to use it for Apple's own services, like iTunes.
Nowadays, the third-party app developers get full access to this tech.
When a user is verified as being “real”, developers get a specially generated signal. To put it simply, the program answers the question: "Is this user a real one?" in a yes-or-no way.
But a “no” does not necessarily mean a user is a bot. The person could just be a new user on a new device. However, the developer can take this signal into consideration when providing access to features in their apps or when running their own additional anti-fraud detection measures, for example.