Computers don’t use names in networking. Instead, they use numbers. This is because computers and similar devices communicate and identify each other over a network using numbers like IP addresses. Humans are used to using names rather than numbers. They can talk directly to others or identify a country, place or thing. To bridge the communication gap between humans and computers and make communication much easier,
DNS stands for Domain Name System. It was created by network engineers. DNS converts domain names into IP addresses. DNS can resolve a website address to a number if it is entered in a web browser. Computers only know numbers. To go to a website, you will open your browser and type the domain name. Let’s say you want to use yahoo.com. Technically, you don’t need to type in yahoo.com in order to find the Yahoo web page. You can type in the IP address if you know what it was.
We aren’t used to dealing with numbers and memorizing them, especially since there are so many websites online, so we can simply type in the domain name and DNS will convert it into an IP address. Now let’s return to our example. If you type in Yahoo.com, your web browser will search its database to find the matching IP address. After it has found it, it will convert that domain name into the Yahoo IP address. Then, once it is done, your computer can communicate to a Yahoo server to retrieve the webpage. DNS is basically a phone book. If you need to find a particular number, you don’t have to search.
You must first look up the number. Then, it will give the number. This will allow us to examine the DNS process in more detail. If your web browser cannot find the IP address in its cache memory, or if it isn’t able to locate it in the browser’s cache memory, then the DNS server will route the query to the next stage, which is the resolver. Your ISP or Internet service provider is the resolver server. When it receives the query, it checks its cache memory to locate a yahoo.com IP address and if it doesn’t, it will forward the query to the root server is the next level. Root servers are the top of the DNS hierarchy.
There are 13 sets or root servers. They are strategically located around the world by 12 organizations. Root servers do not know the IP addresses of the users. However, they know where to send the resolver. This is the resolver will then ask the TLD server to provide the IP address for yahoo.com. The top level domain servers store the address information of top-level domains like.com,.net,.org, and so forth. This TLD server is responsible for the dot.com domain, which yahoo.com is part of. The TLD server will not know the IP addresses of yahoo.com if it receives a query for the IP address of yahoo.com from a TLD server. The TLD will direct the resolver towards the authoritative name servers. Once again, the resolver will request the authoritative name server for IP.
Yahoo! They are the authoritative name server. They are the final authority. When the authoritative name server receives the query, it will reply with the IP address of yahoo.com. The resolver will then tell your computer the address for yahoo.com. Your computer will be able to retrieve the Yahoo website. Important to remember that the resolver will keep the IP address in its cache memory until it receives another query from yahoo.com.
You don’t need to repeat all of those steps.