Generating random numbers is necessary for a large variety of applications, from games to cryptography, from sampling to forecasting. However, the term random numbers is not actually correct, as the generation of numbers through mathematical formulas is deterministic and does not produce true random numbers, but numbers that look random and are called pseudo-random. True randomness can only be achieved through hardware devices, based on physical processes, and even that can be challenged, as one may consider even the universe to be actually deterministic. Modern C++ provides support for generating pseudo-random numbers through a pseudo-random number library containing number generators and distributions. Theoretically, it can also produce true random numbers, but in practice, those could actually be only pseudo-random.