How exactly do the keywords and URLs in Custom Intent Audiences work in targeting?

There appears to be no documentation on how the keywords and URLs one provides works to target your audience. I would like to know:

1. Do the keywords work via AND or OR logic?
2. What URLs should you be using, your landing page(s) or competitor landing pages, or both?
3. Do the URLs work by scrapping content off the pages and coming up with more keywords?

Thank you.