What is the main role of the DNS recursive resolver?

The primary role of a DNS recursive resolver is to receive DNS queries from clients and make additional requests to fulfill those queries. When a client makes a request to resolve a domain name into an IP address, the recursive resolver acts as an intermediary. It first checks its own cache to see if it has the necessary information. If the information is not present, it will then query other DNS servers, which may include the root servers and other authoritative servers, in order to gather the required data and eventually return the result to the original requester. This process of additional queries is essential for ensuring that the resolver can provide accurate and up-to-date DNS information, particularly when dealing with domains that are not frequently accessed.

While caching is also an important functionality of DNS recursive resolvers, as it helps improve efficiency by reducing the need for repeated queries, the main role is fundamentally about handling the incoming requests and managing the resolution process through further queries.