Statistical power refers to the probability that a statistical test will return an accurate result. For example, if you want to conduct an A/B test on landing pages, statistical power can tell you how likely it is that your test will produce a trust-worthy result, given the sample size you have.
High statistical power means a study is more likely to detect real differences or effects if they exist, while low power indicates a higher risk of missing true effects.
Think of statistical power as a measure of the sensitivity of the test or measurement you are doing. More statistical power will allow you to reliably detect smaller differences.