A random number generator (RNG) is a system or algorithm designed to produce a sequence of numbers that lack any predictable pattern. RNGs are commonly used in various applications, including computer simulations, cryptography, and gaming. They can be classified into two main types: true random number generators, which rely on physical processes, and pseudo-random number generators, which use mathematical formulas to generate numbers that appear random. In digital environments, RNGs play a crucial role in ensuring fairness and security. For example, in online casinos, RNGs determine the outcome of games like slots and poker, ensuring that results are unpredictable and unbiased. In cryptography, RNGs help create secure keys for encrypting sensitive information, making it difficult for unauthorized users to access data.