The pattern always helps you to derive some conclusion as the evidence of what has happened in the past and basis we can find the similarity in the current state. It often helps you out in a way that drives you closer to concluding, it's not necessary that the same thing will occur every time but it helps you to draw some conclusion.
Imagine a situation where you observe that every year during the third week of June you expect rainfall and it is considered the start of the monsoon, since this is more like a pattern you can certainly say that this year also in June you will have a spill of a rainfall.
Another situation is in which you see some pattern in share price behavior and basis you expect the price to make a move, in this case, also you recognize some pattern and you predict the outcome.
In both the situation highlighted above the outcome is based on some pattern analysis however, the certainty of that outcome varies as both the data sets are different one being complex and the other being.