ACME
A protocol for automating certificate issuance and renewal. Clients prove domain control through challenges such as DNS records or HTTP responses.
Definition and sourcesKNOWLEDGE / FROM A TO Z
Glossary
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Clear filtersDNS (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 sourcesDNS 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 sourcesENS
Ethereum Name Service maps readable names to addresses and other resources, for example names ending in .eth. Application support varies. ENS is not an AI tool or a complete replacement for DNS.
Definition and sourcesGlue records
Supporting name-server addresses supplied with DNS delegation. They bootstrap resolution when a server's address depends on the delegated zone.
Definition and sourcesLet's Encrypt
A certificate authority providing certificates through automated ACME. A certificate proves domain control, not business trustworthiness or website-content safety.
Definition and sourcesOCSP stapling
A server attaching a signed certificate-status response during TLS. Usefulness depends on certificate, authority and client support.
Definition and sources