Difference Between IP and DNS

IP vs DNS
 

There are two main namespace methods implemented in the Internet: IP address spaces and Domain naming hierarchy. The Domain names are maintained and translated to IP addresses by the DNS.

What is IP?

IP or the Internet Protocol serves two purposes: defining the rules for the IP addressing system for giving a logical numerical address to each entity in a TCP/IP based network and the routing or transporting data packets from source hosts to destination hosts.

Among these tasks, IP addressing is of vital importance, as it is how the location of an entity or a host (such as a computer or a printer), is recognized in an IP based network. In addition, accurate Routing of data is also achieved through IP addressing.

An IP address is usually a unique 32-bit (IPv4) or 128-bit (IPv6) binary number that is assigned to an entity of a network, by the Internet Assigned Number Authority. For the convenience of the human users, these IP addresses are stored in the format of a decimal number. Given below is an example of an IP address.

IP addresses are of two types: Static IP addresses, which are permanent, and are assigned to a host manually by an administrator, and Dynamic IP addresses, which are assigned anew each time the host is connected to the network by the server using DHCP.

What is DNS?

DNS or the Domain Naming System is a hierarchical system for naming computers or other resources connected to a network. It facilitates the naming of groups of users and resources, disregarding their physical locations, which simplifies things for general users, as they only have to know a URL or an E-mail address to access hosts or resources without worrying about how physically locate them. It also contains a mapping system between domain names and their corresponding IP addresses or physical locations, so that it can locate the hosts or resource indicated by the domain names entered by Users.

A typical domain name, (which is formed according to the rules in DNS protocol) consists of three or more parts (referred to as labels), usually concatenated by dots.

As illustrated above, the Domain Naming hierarchy is formed from the right-most to the left-most of the domain name. In the above example, “com” is the Top-Level Domain name and “differencebetween.com” is a sub-domain of TLD “com”. And www.differencebetween.com is a sub-domain of the sub-domain “differencebetween.com”. When it comes to domain names such as www.example.co.uk, the domain “co” is referred as the Second-Level Domain. Each label can contain up to 63 characters and each domain name cannot exceed a length of 253 characters.

If any domain name is associated with a certain IP address, those names are referred to as Hostnames. For example, www.differencebetween.com and differencebetween.com are  hostnames, while the TLDs such as .com or .org are not, as they are not associated with any IP address.

Domain Name System operates in the form of a hierarchical database, which contains sub-branches referred to as Name servers. When a translation of domain name is requested, if Local DNS name server does not have a record of the certain domain, it sends a request to one of the 13 Root DNS Servers, located worldwide. The root DNS server then contacts the corresponding TLD DNS server (org, com, etc) for cached records of the given domain name. Then the TLD DNS server contacts Authoritative DNS server, which contains details about sub-domains.