Manisier got it pretty well. Imagine an archer versus a knight (and imagine that the knight is very fast and agile). It's a matter of the character's comfort zone. Rushdown characters have the tools (normally speed, combo options, and so on) to be comfortable up close, but often struggle to deal with projectiles directly (though they may cope by getting too close for safe projectile use). Zoner/defensive/campy (terminology largely depends on how technical you're being and how much you dislike the playstyle, since it's often frustrating to deal with if you're not used to it) is the opposite. Though they may have good up-close options (like Robin's Levin Sword), they normally lack good ways to close the gap safely, preferring to pepper the opponent with projectiles until they're forced into a mistake or die from the projectiles. Note that zoning doesn't require projectiles. The following classifications are my personal views, and while aspects of it are generally accepted, others may just be my view on things.
Some examples of characters who are
strongly rushdown oriented include:
While some that have strong rushdown options but can also play a middle-ground style would include:
Whereas characters who are somewhat zoning/defense oriented would be:
And these are
very defensively oriented:
Of course, there are other ways you can classify characters. Melee (
) vs Ranged (
) is an easy one. Floaty (
) versus Fast-faller (
) is another, but that's largely related to combo-ability and aerial speeds, rather than a classification of over-all playstyle.
Generally, if you prefer aggressive play, stick to aggressive characters, while if you prefer more counter-attack or safe play, defensive characters may be better for you.