What is the difference between portal free-rule and user-URL?

What is the difference between portal free-rule and user-URL?

Portal free-rule and user-URL are both used to release the domain name before authentication, but the implementation principle is different so the application scenarios are not the same. free-url resolves the IP address of the domain name in advance through DNS, one free-url usually corresponds to 4 IPs; The user-url is only triggered for HTTP messages and is a string match for the domain name. So user-url is generally used for fuzzy matching and does not necessarily require DNS configuration, whereas free-rule requires DNS for exact matching.