So what's the difference...

...between Jelly and Jam?? I look at both on the shelf, and they have the same labels, same ingredients. Except one says Jelly. The other, Jam. What's up with that?

A: Well, the answer, as others have noted, is that "jelly" is made only from the extracted juices of the fruit, giving a smooth consistency, while "jam" includes seeds and pulp, making for a chunkier texture.
My addendum to this explanation is my own term for the bits added to (or not removed from) jam. I call it "glunk". You heard it here first.