There is logic in this concept - denotation. Its essence is that each name in the world corresponds lot of things. Say, an ordinary chair can take many guises: to be wooden and plastic, with the back and without even a fold-out can be easily. But nonetheless, we are all aware of what is at stake, if we hear this word - "chair". The same fable and genres: Well, if heard «FPS» - once in the head clicks: «Doom + Duke Nukem 3D + Quake + Half-Life divided by four." Finish the arithmetic mean. The question is, what kind of relationship it is the subject of our review.