In the last few years, random number generation has seen an interesting rise in popularity, yet many developers simply accept the generator provided by whatever technology they use. However, good random numbers are critical for many applications, such as encryption and security (or the lack thereof; see 2010's Sony PlayStation 3 security incident that prompted a famous XKCD—https://xkcd.com/221/), simulation, games, statistics, and biology.
As a basic principle: the more random a sequence is, the better. The reason for this is obvious. If any number in a sequence of random numbers is statistically dependent on one of the others, it becomes a pattern that can be predicted, and there is no such thing as predictable randomness. Thus, the numbers in a random sequence have to be statistically independent to qualify as good random numbers.
To get...