A Pseudo-Random Number Generator (PRNG) is a computational algorithm that produces a sequence of numbers that only approximates the properties of random numbers. Unlike true random number generators, which rely on physical processes, PRNGs use mathematical formulas to generate their sequences. This means that if you start with the same initial value, or seed, the output will always be the same. PRNGs are widely used in various applications, including computer simulations, cryptography, and gaming. While they are efficient and fast, their predictability can be a drawback in security-sensitive applications, making it essential to use strong algorithms and seeds to enhance randomness.