These are basic information you need to know to setup your firewall rules
Ips – Each visitor has an ip. Visitors are tracked thanks to Internet ip system. IP (Internet Protocol) like 54.39.98.144, which is YOUR ip, is a unique address that identifies a unique device (or network) on the internet.
Host – A Host or Hostname is a computer which acts in most cases ”without the human intervention”. It exchanges or collects data, offers services..etc, but whether it has malicious or legitimate activity, that depends!
URL – URL is nothing more than the address of a given page on the Web. For example, current page url is: https://www.geniusplugin.com/faq/. The url is always seen on the browser address bar. To access a url (web address), you may click on a link, or write it manually on the browser address bar.