Biological differences: on a physical level (strength, height, speed) these are relatively dimorphic (large d value, if you want to get technical about it - difference between means of the male and female populations divided by the square root of the product of their standard deviations - it's a measure of how distinct the bell curves are). For mental/neurological differences, insofar as any can be replicably measured, the d values are tiny - the curves largely overlap.
So it's quite possible to say that men and women are biologically different when it comes to physical strength (hence women don't particularly want to share overnight spaces with strange men, a small but non-negligible percentage of whom may want to do them harm), but hold that there aren't many cognitive differences, so there's no reason (for instance) not to employ women in STEM subjects. No contradiction at all. (See picture - d values for, say, height, are round about 2, d-values for cognitive differences insofar as any studies have found them - and not all have - are less than 0.5)
Also - even if the d values were bigger, this still wouldn't be a basis for tailoring your education system or employment system differently for the two sexes. Even if, say, only 10% of women wanted to and/or had the aptitude to become engineers, it wouldn't be right to deny these women the opportunity to try. (In fairness to Peterson, I think he'd agree with this, from what I've read).
Talking about biological differences is actually quite nuanced.
(What I can't get my head round is the trans activists who argue that there's no physical difference, so male-bodied transwomen should be included in women's sport, but there is a difference in brains, which allegedly explains how it's possible to have a "ladybrain" in the "wrong" body).