Randomness is a lack of order, purpose, cause, or predictability.
However, it is still possible to make predictions involving randomness, because randomness tends to average out over time. For example, while nobody can predict the result of a coin toss, it is easy to predict that the coin should land either heads or tails approximately half the time. As a more advanced example, the motions of molecules are random, but it is possible to predict that randomly distributed molecules of water will come together in an ordered structure (ice) when the temperature drops far enough. The ability to make these predictions is an important part of statistics.