It is a biological system. The subjective terms used in neuroscience are only approximate. Objective events appear to be members of familiar classes. Perceived events are almost always familiar events. Real objects are physically labeled or they can't be perceived.
Labels imply categories with distinct boundaries or functions.
Knowing something means imposing convenient boundaries upon it. Knowing something means giving it a name or label. The members of a sensory category are always exactly alike. Natural categories normally have well-defined limits. Neuroscientists often use terms like explicit, objective, and global to distinguish between one kind of neural behavior and another.