Image courtesy of Flicker fyuryu
Randomness is the mathematics of the unpredictable. Dice and roulette wheels produce random numbers: those which are unpredictable and display no pattern. But mathematicians also talk of 'pseudorandom' numbers - those which appear to be random but are not.
Melvyn Bragg and his guests on the BBC radio 4 series "In Our Time" discuss randomness and pseudorandomness.