The paper by V. Vedral and M.B. Plenio improves the conditions for entanglement measures and presents a class of entanglement measures that satisfy these conditions. They show that the Quantum Relative Entropy and Bures Metric generate two measures in this class. The authors calculate the entanglement measures for several mixed two-spin 1/2 systems using the Quantum Relative Entropy and provide an efficient numerical method to compute these measures. They prove several properties of their entanglement measure, which have important physical implications. The statistical basis of the Quantum Relative Entropy as an entanglement measure is explained, and it is argued that the measure of entanglement generated by the Quantum Relative Entropy provides an upper bound to the number of singlet states that can be distilled from a given state. The paper also discusses the purification procedures and their relation to entanglement, showing that the distillable entanglement is generally smaller than the entanglement of creation.The paper by V. Vedral and M.B. Plenio improves the conditions for entanglement measures and presents a class of entanglement measures that satisfy these conditions. They show that the Quantum Relative Entropy and Bures Metric generate two measures in this class. The authors calculate the entanglement measures for several mixed two-spin 1/2 systems using the Quantum Relative Entropy and provide an efficient numerical method to compute these measures. They prove several properties of their entanglement measure, which have important physical implications. The statistical basis of the Quantum Relative Entropy as an entanglement measure is explained, and it is argued that the measure of entanglement generated by the Quantum Relative Entropy provides an upper bound to the number of singlet states that can be distilled from a given state. The paper also discusses the purification procedures and their relation to entanglement, showing that the distillable entanglement is generally smaller than the entanglement of creation.