  Quantum correlation includes quantum entanglement and quantum discord. Both
entanglement and discord have a common necessary condition--------quantum
coherence or quantum superposition. In this paper, we attempt to give an
alternative understanding of how quantum correlation is related to quantum
coherence. We divide the coherence of a quantum state into several classes and
find the complete coincidence between geometric (symmetric and asymmetric)
quantum discords and some particular classes of quantum coherence. We propose a
revised measure for total coherence and find that this measure can lead to a
symmetric version of geometric quantum correlation which is analytic for two
qubits. In particular, this measure can also arrive at a monogamy equality on
the distribution of quantum coherence. Finally, we also quantify a remaining
type of quantum coherence and find that for two qubits it is directly connected
with quantum nonlocality.
