Name resolution using caching servers

Query from a stub resolver to a caching server
recursive query: requiring all the resolution procedure
Name resolution by caching server
always begin with a query to a root name server
root servers' addresses are provided separately
built in the implementation / "hint file"
if the response indicates a delegation, continue the process at the specified server
repeat that until it reaches the zone that has the authority of the query name
all the responses are cached for future (re)use
Note: each query in theses steps are non-recursive
If the queried name is cached
simply return the cached data
TTL is decreasing