random number generator - technical definition

A program routine that produces a random number. Random numbers are created easily in a computer, since there are many random events that take place such as the duration between keystrokes. Only a few milliseconds' difference is enough to seed a random number generation routine with a different starting number each time.

Once seeded, an algorithm computes different numbers throughout the session. The numbers that are created must be distributed evenly over a certain range, and they cannot be predictable (the next number cannot be determined from the last).