The DNS is considered a fundamental part of the Internet as it would not survive without it. For example, try to reach something.com; this “something.com” has to be transformed into an IP address like “103.287.145.155” so that the browser, say Chrome, gets to know which server to contact.
- DNS: The DNS holds for Domain Name System. The apparent intention of DNS is to translate domain names to IP addresses. Thus, even though there are domain names for all the websites, IP addresses are also for them. The Internet uses these IP addresses to identify the websites. The IP address is numerical data incorporated with four parts separated by dots(.). The DNS is a comprehensive network that collectively creates a database of domain names and IP addresses. This database is a global one. The hierarchy consists of DNS servers.
- DNS Server: A DNS server is additionally a web server. Its principal objective is to interact with the database mentioned above. These DNS servers translate the domain name into the URL area of a web browser to the corresponding IP address.
- FQDN is the domain name that designates its exact location in the DNS hierarchy. It identifies all domain levels, including the top-level domain and the root zone. It consists of two components, the hostname and the domain name. For example, an instance of FQDN in a mail server is “mail.mydomain.com,” where “mail” is the hostname, and “mydomain.com” is the domain name.
- DNS ROOT ZONE: DNS root zone is the most powerful level in the DNS hierarchy. The root name server is the server to the root zone. It answers the calls for records in the root zone and answers other requests by implementing a schedule of authoritative name servers for the relevant TLD (top-level domain). These are the authoritative nameservers that assist the DNS root zone. These servers include the global list of the top-level domains and contain:
- Organizational hierarchy .com, .net, .org.
- Geographic hierarchy .uk, .fr, .pe.
- Top-level domains: The subsequent level in the DNS hierarchy is Top-level domains. There are multiple TLDs available at the instant. It has been noticed; the TLDs are classified into two subcategories. They are organizational hierarchy and geographic hierarchy.
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In the geographic hierarchy, every country is assigned two-letter codes. These codes are related to identifying countries. For instance, take the domain name images.google.com. where the “.com” is the top-level domain. It is described as TLD in short. It is the next element in the DNS hierarchy. A TLD can have multiple domains under it. For instance, a .com TLD can hold centos.com, linux.com, ubuntu.com, etc.
- SECOND LEVEL DOMAINS: The following level in the DNS hierarchy is the Second-Level Domains. It is the domain that is directly below the tld. It is the central part of the domain name. It can modify according to the buyer. There are no boundaries here as the TLDs. Once the domain is ready, anyone can buy it. If the part is unavailable, the same 2nd level name with other TLDs is the most suitable choice.
- Sub-domain: The sub-domain is the subsequent level in the DNS hierarchy. The sub-domain can be described as the domain that is a division of the main domain. The unique domain that is not also a subdomain is the root domain. Assume two domains. one.example.com and two.example.com. You can understand that given domains are the sub-domains of the main domain example.com, and example.com is also a subdomain of the .com top-level domain.