Statistical significance is the probability that there is a true difference in performance between your variant and its control. It is the probability that the difference in the goal metric between variant and control is not due to random chance.
Statistical significance allows us to understand when results are true, versus when they might be due to noise. For most businesses, generally, everything under 80% is considered not significant. Figures between 80 and 95% are directional or moderate, and anything above 95% is high.