Jaws is very much a spiritual child of Moby Dick, with a Great White Shark inserted in place of a giant white whale.
The hunting of the shark means something different for each of the three main male leads. For Brody, killing the shark would mean ensuring the safety of his children (the relationship between parents and their children being a strong running theme in nearly all of Spielberg's films). For Hooper, the shark is just another shark. It's his job to study them and provide his expertise. That's it. Then there's Quint, a Captain Ahab like figure whose obsession places him in a fit of blind fury. To him, all sharks are the same and killing this one would operate as ultimate revenge.
And like Moby Dick, Jaws is a perfectly told straightforward story depicting believable human beings and observing human behavior. Part of the joy of Jaws is watching these characters interact with each other in ways that make them seem truly alive and real, which only serves to make the threat of the shark even more threatening. We also have the land scenes of the first half that expose the stakes at the same time as it depicts the conflict between Brody and the mayor who wants to keep the beach open.
And of course, the film is marvelously constructed by Spielberg. Much is made of the way he directs the scenes of suspense, but there's also very intelligent decisions being made in non-action scenes. Many shots burned into my eyes are something as simple as a quiet moment between a father and his son who is innocently ignorant of the danger at hand.
