 For any two distinct quantum states, \(\rho\), \(\omega\), and any real number between 0 and 1, there is a corresponding mixed state. The probability assigned to any experimental outcome by this mixed state is \(p\) times the probability it is assigned by \(\rho\) plus \(1-p\) times the probability assigned to it by \(\omega\). One way to physically realize the preparation of a mixed state is to employ a randomizing device, for example, a coin with probability \(p\) of landing heads and probability \(1-p\) of landing tails, and to use it to choose between preparing state \(\rho\) and preparing state \(\omega\). We will see another way to prepare a mixed state after we have discussed entanglement, in section 3. A state that is not a mixture of any two distinct states is called a pure state.