Question: What defines newer?

What makes a page "newer"?

My Welcome Visitors page seems to have ten or so "newer", but I doubt that people forked my page and extended it. My hypothesis is that it's just other pages with the same name, edited more recently in time, with no idea about ancestry.

Note that the link to Welcome Visitors will link to your page, not mine (I think), so you can't see what I see. See Question: Must I fork a page to link to it?