@hazardwarning I can try, and there's help at hand here [indieweb.org].
Essentially, it identifies as particular URL as belonging to you. That's because only you can add the information needed to do that. So, for example, presumably only you can edit your Twitter profile. And in that profile, you can put your website address. That could be your site here at 10C (although that adds a layer of complexity, because at the moment it requires Jason to do the next step (I think).
In your website address -- that is, and address where you potentially control **all* the code -- you can now add a link to your Twitter profile, with the rel="me" added. It can be in your head, or it can be an actual link on the page. And that tells any website that visits your site that your Twitter account is also "yours".
It is one of the bits of glue that allows the #indieweb to work, by joining together different sites and accounts.
I can try to answer any further questions at a non-geeky level, because that's the level I am at, about 1 micron above you.