Statistical Significance - is the likelihood that a relationship between two variables or difference between two data sets is caused by something else other than chance. It uses the concept of significance level (α). α is the maximum probability of rejecting the null hypothesis (Ho) when it is true i.e. maximum probability of committing Type I error. The calculated probability (p) of committing type I error is compared with α and the result is considered statistically significant if p < α.
An application oriented question on the topic along with responses can be seen below. The best answer was provided by Mohan PB on 15th October 2017.