When you make changes to your zone, you are making changes on the host.A resolver is a DNS server that will send requests to other DNS servers for the records from their zones in an attempt to answer the requests that it receives.In order to make a call, the phone that initiates the connection must have the number of the line to which it wants to connect.
DNS servers can handle one or both of two primary functions: DNS host and resolver.
DNS hosts hold the zones for their domains and answer requests with the records from the zones for those domains.
In each record in the zone, there is a Time To Live (TTL) value that specifies (in seconds) how long a resolver should cache the record.
One technique to reduce the time it takes for changes to propagate is to reduce the TTL value in the current zone prior to making changes, however the change in the TTL on the record itself will take the length of time specified in original TTL value to propagate before propagation period is lowered for further changes.
The DNS lookup process requires your local DNS server to ask others servers if it is not authoritative for the domain you are trying to reach, it should ask other servers to get an answer.
Your local server could get quite busy performing these lookup requests and this could slow down its performance if it has to perform a lookup for every request.The same process applies for all other services (such as email, chat or games) on the internet.DNS records function similar to a phone book, relating domain names with IP addresses so that these services can be reached.This means that all custom TTL records set will unfortunately not be honored, as Host Gator does not allow custom TTL.Additionally, most computers cache DNS which can cause the computer to "remember" the old IP address for up to 48 hours until the next time it updates.These sort of requests are called recursive requests.