How DNS Works

When you type a domain name in your browser, it first looks at your local hosts file.

If the domain is not there, it goes to your local DNS resolver. This resolver checks its cache or configuration for the preferred DNS server that handles the zone for this domain.

If still no match, it sends the query to the root servers. The resolution then works top-down, recursively.

The process from client to local DNS server is recursive. But the interaction between DNS servers themselves is iterative.