What the Pearson correlation below means? (I've answered the question below it, but I don't understand the significance of what the r2 actually means.

D.6.8.2.b. What is r2 for the Pearson correlation and what does it mean?

The r2 for the Pearson correlation is .34 and p is .003, with 75 participants with both variables of math achievement and mothers education, written as r(73) = .34, p=.003, with the 73 showing the degrees of freedom, and the p value (.003) showing the statistical significance (Morgan et al., 2020).