DNS (Domain Name System)
A hierarchical, distributed naming system. DNS records can identify IP addresses, mail servers and other information. A domain need not correspond to one website or server; DNS answers are also cached.
Definition and sourcesKNOWLEDGE / FROM A TO Z
Glossary
Technology, explained clearly. Find a term, choose a letter or narrow the topic. Definitions include sources and their review date.
Terms 19 / 685
Clear filtersDNS A record
A DNS record mapping a name to an IPv4 address. It does not redirect URLs or itself configure HTTPS; those belong to other layers.
Definition and sourcesDNS AAAA record
A DNS record mapping a name to an IPv6 address. It should point to a working IPv6 service; incorrect records can harm some users.
Definition and sourcesDNS CAA record
A record specifying which certificate authorities may issue for a domain. Incorrect policy can prevent certificate issuance or renewal.
Definition and sourcesDNS CNAME record
A DNS record identifying an alias's canonical name. It is not an HTTP redirect and generally cannot coexist with other DNS data at that name.
Definition and sourcesDNS MX record
A DNS record naming a domain's receiving mail server and priority. Lower numbers mean higher preference; MX does not configure application email sending.
Definition and sourcesDNS NS record
A record naming an authoritative server for a zone. Registry delegation and zone records need consistency; editing a zone alone may not change delegation.
Definition and sourcesDNS over HTTPS
Sending DNS queries over HTTPS. It protects transport between client and resolver, but the resolver still sees queries; it does not replace DNSSEC.
Definition and sourcesDNS over TLS
Sending DNS over a TLS-encrypted channel, usually on port 853. Transport protection does not hide queries from the chosen resolver.
Definition and sourcesDNS propagation
A colloquial name for DNS changes becoming visible as cached copies expire. It is not one global switch; TTL and the user's resolver matter.
Definition and sourcesDNS PTR record
A record pointing to a name, commonly used in reverse DNS. For public IPs, the address provider usually configures it rather than any domain administrator.
Definition and sourcesDNS server
A service handling DNS-data queries. Recursive resolvers and authoritative servers have different roles; not every server should allow public recursion.
Definition and sourcesDNS SRV record
A record locating a service by host, port, priority and weight. Clients must support SRV; it does not automatically relocate every web service.
Definition and sourcesDNS TXT record
A text-bearing DNS record used for domain verification and mail policies. The applicable specification or service defines its value's meaning.
Definition and sourcesDNS-based Authentication of Named Entities
A mechanism publishing TLS authentication information in DNSSEC-protected TLSA records. DANE requires client support and a valid DNSSEC chain.
Definition and sourcesDNSSEC
DNS extensions authenticating response origin and integrity through signatures. DNSSEC does not encrypt queries or certify a website's safety.
Definition and sourcesDomain name
A name within the DNS hierarchy, such as syntimo.com. It can support websites, email and other services. A domain is neither the website nor hosting; registration does not automatically create content.
Definition and sourcesDomain registrant change
A change of the domain registrant holding registration rights. It differs from transferring management to another registrar.
Definition and sourcesDomain transfer authorisation code
An authorisation code used to transfer a domain between registrars. Keep it confidential; procedures and code validity depend on the domain registry.
Definition and sources