A qubit, or quantum bit, is the smallest unit of quantum information. It's a single quantum state that can be in two states simultaneously, which is just fancy for "it can be both yes and no at the same time, but don't ask me how."
Quantum entanglement, on the other hand, is when two or more qubits get all buddy-buddy and can't be separated, even when they're on opposite sides of the universe. It's like they're stuck in some kind of quantum relationship, where they're always connected, always in sync, and always driving each other crazy.
And that's just the beginning! If you want to learn more about the weird world of quantum computing, just click one of the links above or check out our Quantum FAQ for more info.