Wiki is the new Google huh
I think vans generally carry at least 7 people standard. Plus they are mated with a V6 engine. Geared toward families on a budget.
SUVs are a bit bulkier, may be heavier, carry 5 people standard (unless you put in an optional rear seat), and usually come with a gas hogging V8.
SUVs are usually more for looks and status rather than purpose, which is what minivans are for. Which would explain the big cost difference between the two.