Which stands for Domain Name System, is like a phone book for the internet. It's a system that helps translate human-readable domain names (like www.example.com) into computer-readable IP addresses (like 192.0.2.1). In simple terms, DNS helps your computer find the right website when you type a domain name in your web browser.
Here's how DNS works:
- When you type a domain name in your web browser, your computer sends a request to a DNS resolver (usually provided by your internet service provider or ISP). The resolver acts like a middleman between your computer and the internet.
- The DNS resolver first checks its local cache to see if it already knows the corresponding IP address for the domain name. If it has the information, it sends it back to your computer, and the connection to the website is established.
- If the DNS resolver doesn't have the IP address in its cache, it starts a process called DNS resolution. It acts as a detective and starts asking other DNS servers for help.
- The resolver contacts a root DNS server to ask for information about the top-level domain (TLD) of the website (e.g., .com, .org). The root server directs the resolver to the DNS server responsible for that TLD.
- The resolver then contacts the TLD DNS server and asks for information about the specific domain name (e.g., example.com). The TLD server may either respond with the IP address directly or provide the resolver with the address of the authoritative DNS server for the domain.
- The resolver then contacts the authoritative DNS server for the domain and requests the IP address of the website. The authoritative server has the final say on the IP address associated with the domain.
- The authoritative DNS server responds to the resolver with the IP address.
- The resolver caches the IP address locally for future use and sends it back to your computer.
- With the IP address in hand, your computer can establish a connection with the web server hosting the website you wanted to visit.
This entire process happens in the background within a fraction of a second, enabling you to access websites by simply typing domain names. DNS plays a crucial role in making the internet more user-friendly by translating human-readable names into IP addresses that computers can understand.
There are several types of DNS (Domain Name System) records related to names (also known as NAME records) that can be associated with a domain. Here are some commonly used ones:
- A (Address) Record: The A record maps a domain name to an IPv4 address. It associates a domain name with the specific IP address where the website or server is hosted.
- AAAA (IPv6 Address) Record: The AAAA record maps a domain name to an IPv6 address. It is similar to the A record but used for IPv6 addresses, which are longer and allow for a larger pool of unique addresses.
- CNAME (Canonical Name) Record: The CNAME record creates an alias or alternative name for a domain. It maps one domain name to another domain name. For example, you can create a CNAME record to map "www.example.com" to "example.com".
- MX (Mail Exchanger) Record: The MX record specifies the mail server responsible for handling email delivery for a domain. It identifies the domain's email server(s) where incoming emails should be sent.
- NS (Name Server) Record: The NS record indicates the authoritative DNS servers responsible for a domain. It specifies the nameservers that should be queried to obtain DNS information for the domain.
- TXT (Text) Record: The TXT record is used to store arbitrary text data associated with a domain. It is commonly used for various purposes like domain verification, SPF (Sender Policy Framework) configuration, and more.
- SRV (Service) Record: The SRV record defines the location of a specific service or application available within a domain. It specifies the hostname, port, protocol, and priority of the service.
These are some of the main types of NAME records used in DNS. Each record serves a specific purpose and helps direct traffic and services associated with a domain. The configuration and usage of these records depend on the specific needs of your domain and the services you want to set up.