I don't understand the figures mentioned in the analysis

Hello everyone,

I've been using squaresspace for some time now and I must say I'm extremely satisfied - I'd like to thank the team for all their hard work. 

I just have one question that's bothering me: when I follow the site's analysis results, I regularly see figures that I don't understand because they don't make much sense to me.

For example, I often have a number of visits higher than the number of unique visitors, which is normal up to that point, but then I have a number of page views much lower than the number of unique visitors. 
And here I don't understand, because if a unique visitor doesn't stay on my site, he'll at least have seen the home page, so one.

Could someone explain to me how to interpret these figures?

With my thanks