Rose refers to the Titanic as the ship of dreams…and that's pretty much what it represents to a bunch of the characters.

Why? A few reasons, based on real life for added oomph:

• The Titanic was a huge step forward in terms of nautical technology. Not only was this impressive on its own (who doesn't like boats?), but it also foreshadowed the wave of technological innovation that would occur in the 20th century. Yeah. People knew that the times, they were a'changing.
• The ship represented opportunity. Don't forget that transatlantic travel wasn't nearly as common in 1912 as it is today, so the opportunity to cruise on over from Europe to America was a big deal. And to do it on a fancy new ship? A total adventure.

The Ship of Nightmares

Of course, there's another side to Titanic's symbolism that has nothing to do with ingenuity or adventure. For people like Cal and Mr. Ismay, the Titanic is all about basking in luxury and showing off your status and power to other people. Fun times.

Rose finds Mr. Ismay's obsession with Titanic's size so off-putting that she suggests he go read some Freud:

MOLLY: Hey, uh, who thought of the name Titanic? Was it you, Bruce?

ISMAY: Yes, actually. I wanted to convey sheer size, and size means stability, luxury, and above all, strength.

ROSE: Do you know of Dr. Freud, Mr. Ismay? His ideas about the male preoccupation with size might be of particular interest to you.

Oof.

And then, of course, there's the fact that the ship sinks, which kind of undermines its power as a symbol of hope and opportunity. Nonetheless, at the end of the movie, Jack claims that he's still super glad he got on the Titanic, because of the (brief) opportunity it gave him to know Rose.

Aww, dang. That's some Romeo and Juliet-level morbid sweetness.

Perhaps the bottom line is that the Titanic is a metaphor for life's big adventures: however they turn out, they should be cherished for the opportunities they provide for human connection and adventure—and not, you know, for showing off how rich you are.

After all, Mr. Ismay's desire to show off Titanic's speed pretty much led to the ship's downfall. And we mean "downfall" literally, as in the ship literally fell down to the bottom of the sea. Splat.