Glossary
The small website glossary
Plain answers to the words that come up when you set up a small website or a domain: records, redirects, parking and the rest.
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A
- A record An A record is a DNS entry that links a domain name to an IPv4 address, the number a server answers on. It is the usual way to point a bare domain such as example.com at a website.
- Alt text Alt text, short for alternative text, is a brief written description attached to an image on a web page. Screen readers read it aloud for people who cannot see the image, and browsers show it when the image does not load.
- Apex domain An apex domain is your domain name with nothing in front of it, such as example.com rather than www.example.com. It is also called the root, bare or naked domain, and it follows stricter DNS rules than a subdomain.
- Auto-renew grace period The auto-renew grace period is a short window after a domain's expiry date during which it can often still be renewed at the usual price. Its length and rules depend on the registry and the registrar, so it is a safety net, not a plan.
C
- CAA record A CAA record is a DNS entry that lists which certificate authorities are allowed to issue SSL certificates for your domain. If a CAA record exists and leaves an authority out, that authority must refuse to issue one.
- CNAME record A CNAME record is a DNS entry that makes one name an alias of another name. Instead of pointing at a server's number, it says "look up that other name and use its answer", which is why it suits subdomains such as www.
D
- DKIM DKIM, DomainKeys Identified Mail, adds a digital signature to each email you send. You publish a matching public key in DNS, so receiving servers can check that the message really came from your domain and was not altered on the way.
- DMARC DMARC is a DNS record that tells receiving mail servers what to do with email that claims to be from your domain but fails the SPF and DKIM checks. It can also ask them to send you reports about what they see.
- DNS propagation DNS propagation is the period after you change a DNS record when some people still see the old answer. It happens because resolvers around the internet keep a cached copy until its time to live runs out.