As mentioned in the introduction to Oscars, the Oscar or Astronotus ocellatus belongs of the Cichlidae family (commonly known as Cichlids). As such, its behaviour is not dissimilar to other cichlids. Cichlids, though varying in body shape, size, colour and breeding style do have something in common - intelligence, which is not oft seen in other types of fishes.
The Oscar family is popularly referred to as the peacock cichlid or velvet cichlid, especially to American and UK aquarists. I suppose this is due to the beautiful markings on the Oscar Cichlids - the ocellatus or "eye" which is prominently seen on the side of the Oscar's body just like how it appears on a peacock's feather. It is almost like a false eye by the side of the body to deter other fishes from coming near, though I must say that Oscars are usually aggresive in nature and fear no other fishes (unless they are far too big).
I understand that the original scientific name for the Oscar is Lobotes ocellatus as given by Baron Cuvier in the 1800s, though I have no idea how it became the Astronotus ocellatus. Personally, with no disrespect to Baron Cuvier, I prefer the current scientific name for the Oscar.