Almost all of the names in the Harry Potter series are significant. Sirius Black means, virtually, Black Dog; the name Remus Lupin has its origins in the Latin word wolf, and in a co-founder of Rome, Remus, who was suckled by a wolf. Take also, for example, Lucius Malfoy: the "mal" in numerous languages is rooted in the word "bad," and his first name, Lucius, is similar to Lucifer. Other names, like Dumbledore, have actual definitions—in this case, bumblebee in old English. One can liken this to Dumbledore, who is an ancient, wise wizard who works well and hard to sustain his community, the "hive" of Hogwarts. Professor Trelawney's first name is Sibyll, the ancient prophet of mythology. Furthermore, Padfoot, Moony, Wormtail, and Prongs all are indicative of the animal they represent.
Quidditch as a social indicator
The Quidditch game between Gryffindor and Slytherin represents each of the teams perfectly. The Slytherins attempt to injure Harry the week before the game, and when the day of the match arrives, they play a dirty game, knocking players from their broomsticks during the game, grabbing Gryffindor heads and broomsticks instead of simply the balls. The Slytherins fly poorly on very good broomsticks (bought by Malfoy's father so that Malfoy could play on the team). Futhermore, the Slytherin team is not integrated at all: they have a team of only boys, unlike the Gryffindor team, compiled of seven highly skilled, well-practiced girls and boys, flying on a full array of differently-priced broomsticks. Gryffindor plays fairly but retaliates hard, and Harry beats Malfoy to the Snitch, despite Malfoy's many efforts to halt Harry's progress.