It must be jelly ...

[DOUBRIS]

What's the difference between jelly and jam?

[jbeputnam]

If you're talking about American/British terms, then they are both one and the same. Americans call it jelly, we call it jam. If you're talking about the difference between the wobbly stuff and jam, then it's simply that jelly contains gelatine, and jam doesn't.

[rekstout]

A jelly such as redcurrant jelly (served with lamb etc.) is basically a strained jam and usually a bit sharper.

[aloha]

Actually, Jelly is clear and Jam still has the bits of the fruit in it.