True or False: DNS stores information in the form of resource records.
The correct answer and explanation is:
True. DNS (Domain Name System) stores information in the form of resource records (RRs). These records contain key information about domain names and their associated data. A resource record consists of several fields, such as the domain name, record type, time-to-live (TTL), and the data value.
The most common types of DNS resource records include:
- A record (Address Record) – maps a domain name to an IPv4 address.
- AAAA record – maps a domain name to an IPv6 address.
- MX record (Mail Exchange Record) – specifies mail servers responsible for receiving email messages for a domain.
- CNAME record (Canonical Name Record) – allows one domain name to be an alias for another.
- NS record (Name Server Record) – indicates the authoritative DNS servers for a domain.
- TXT record – stores arbitrary text data, often used for domain verification and security purposes like SPF or DKIM for email authentication.
- PTR record (Pointer Record) – maps an IP address to a domain name, often used in reverse DNS lookups.
Each resource record provides the necessary information to resolve queries. For example, when a user types a domain name in a web browser, the DNS resolves the domain to an IP address using A or AAAA records. The DNS system is hierarchical, meaning that it starts with the root DNS servers and works its way down through authoritative name servers that store the actual resource records for specific domains.
The TTL in each resource record determines how long the record is cached by DNS resolvers before a new lookup is performed. This ensures efficient management of DNS traffic and helps reduce the load on authoritative servers. In summary, DNS uses resource records to map human-readable domain names to machine-readable data, ensuring that users can access websites and other internet services.