DNS stands for Domain Name System. All computers on an internet are uniquely identified by their IP address. The IP address is in the format of: 184.108.40.206. As you can see, it is very hard for users to remember this unique number. However, it is very easy to remember a name like: example.com. DNS resolve human-readable domain names like example.com to its IP address so that users don't have to remember the complex number. Its also provide other information like main server etc.
DNS report shows each record for any domain name.
SOA record (Start of Authority), which consist of crucial information like the
SERIAL number, which is monitor by other name servers for change, which indicates to them a change in information for a zone, REFRESH which tell how often a secondary name server should check for a change in the serial number, RETRY is to inform a secondary server how long it should use it current entry if it is unable to perform a refresh and MINIMUM is how long the other name servers should hold these information.
NS record which show the authoritative DNS for the zone A record which points a hostname to an IP address
CNAME record (canonical naming) which allows a node to be address using more than one hostname
MX record, which is used for message routing where there are multiple mail exchange hosts. A (A) record host address is needed for every MX record set.
PTR records, which are just the reverse of A records, it maps IP address to a hostname. These records can only be meaningful in-addr.arpa zones have been delegated to your control by your service provider of your IP block.
There are also some other lesser used record types like HINFO which indicate CPU and operating system types for mapping to specific hostnames and Text (TXT) record that provides a descriptive text associated with a domain name.