Domain record: Domain record is used to store the information related to a domain. There are different types of records used to save different type of information. For Example, IP address associated with a domain record is stored in the address record and geographical location of a domain is saved in the location record.
DNS zone: Domain records are further classified in to zones. DNS (Domain name System) zone is used to manage the administrative responsibilities associated with a domain. A zone is used for mapping domains to the resources in the internet.
Name server: A name server is used to store the DNS zones. Usually, two name servers are used to store the DNS zones. However, even a single name server, or many name servers can be used to store DNS zones. A name server actually resolves a domain name to its corresponding IP address. This concept is known as forward DNS.
Domain lookup and cache: A computer doesn’t always looks up a domain every time a user wants to access it. Instead, it uses a cache to store the information about a particular domain. A cache server is used for this purpose. If you have moved your website from one internet host to another then you will know that domain propagation takes some time. This time is actually taken by the cache server to clear its cache and update the information of the new name server.
MX record: MX record stands for Mail Exchanger record. MX record has information about host name of an incoming mail server. Also, it has a numeric preference value. MX record is used by the email program to look up host name and then it contacts the mail server.
Reverse DNS: Reverse DNS is used to find a host name with the help of a IP address. For Example: if you have an IP address, like 184.108.40.206, and if you do the reverse DNS you can find the host name, ISP, organization, type, assignment and other information related to geo-location.