We solve the entanglement classification under stochastic local operations and classical communication
(SLOCC) for general n-qubit states. For two arbitrary pure n-qubit states connected via local operations,
we establish an equation between the two coefficient matrices associated with the states. The rank of the
coefficient matrix is preserved under SLOCC and gives rise to a simple way of partitioning all the pure
states of n qubits into different families of entanglement classes, as exemplified here. When applied to the
symmetric states, this approach reveals that all the Dicke states |l,n> with l=1,..., [n/2] are
inequivalent under SLOCC.