The correlation was 0. We then have to calculate the power of the study. The post-hoc power I got was .

For a university assignment, I've been given data to conduct a pearson's correlation. The correlation was 0.577. 

We then have to calculate the power of the study. The post-hoc power I got was .96. 

I am struggling to interpret this- I'm not actually sure what this power means, and what the point of doing a post-hoc power analysis is? Any help would be greatly appreciated!