Novelty (derived from Latin word novus for "new") is the quality of being new, or following from that, of being striking, original or unusual.
[1] Novelty may be the shared experience of a new cultural phenomenon or the subjective perception of an individual.
[2] From the meaning of being unusual usage is derived the concept of the novelty dance (a type of dance that is popular for being unusual or humorous); the novelty song (a musical item that capitalizes on something new, unusual, or a current fad); the novelty show (a competition or display in which exhibits or specimens are in way some novel); and novelty architecture (a building or other structure that is interesting because it has an amusing design).
It is also this sense that applies to a novelty item, a small manufactured adornment, toy or collectible.
[5] A novelty effect is the tendency for performance to initially improve when new technology is instituted.