  In this Letter we discuss the entanglement near a quantum phase transition by
analyzing the properties of the concurrence for a class of exactly solvable
models in one dimension. We find that entanglement can be classified in the
framework of scaling theory. Further, we reveal a profound difference between
classical correlations and the non-local quantum correlation, entanglement: the
correlation length diverges at the phase transition, whereas entanglement in
general remains short ranged.
