# Name Server and Configuration(DNS)

DNS is a technique of mapping of IP address to readable names(Domain Name) and readalble names(Domain Name) into IP address.
DNS helps to ease in searching the website by assigning names to each serving host a domain name for end users.

A hostname can be either a simple name, such as solaris or freebsd, or a fully qualified domain name '(FQDN),such as solaris.unpbook.com.

Technical Terms in DNS:
1. NameServer
2. Zones
3. Resource Records
4. Lookup(Forward and Reverse Lookup)
5. Delegation
6. Master and Slave NameServer

# Resource Record

Resource Record, Simply can be as called as Database for DNS zones and contains the fields that helps in mapping the IP address and Domain Names.
Resource Record are present in the zones files in the DNS server where the looksup or queries are performed.

Some types of Resource Record
1. NS : Name of the hostname or DNS server
2. SOA : start of the authority containing the
administrative information of the zone.
4. A : maps the NS into the IPV4 address
5. AAAA : maps the NS into the IPV6 address
6. PTR : pointer record that maps the IP address into domain name of the system or host.
7. MX : mail exchanger
8. CNAME:CNAME stands for "canonical name." A common use is to assign CNAME records forcommon services, such as ftp and www. If people use these service names instead ofthe actual hostnames, it is transparent when a service is moved to another host.

# Resolver and NameServer