Significance level is the probability that the null hypothesis rejected is in fact true. If we say there is a significance level of 0.10 or 10%(α=0.10 level) then there is a 10% chance of incorrectly rejecting the null hypothesis when there is actually no difference.
If we wish to reach a conclusion on rejection or acceptance of the null hypothesis, we could use the p value(the probability that observed results or more extremee results are true given null hypothesis)which we compare with the significance level to conclude. If the significance level is 0.10 and p value is 0.07(since p value is less than significance level) , we reject the null hypothesis and vice versa.
