Web data, explained plainly
40 terms you meet when working with domains, DNS, email security, SEO and scraping.
A DNS record that points a hostname to an IPv4 address.
A DNS record that points a hostname to an IPv6 address.
Brand Indicators for Message Identification: shows a brand logo next to authenticated email.
A DNS record that lists which certificate authorities may issue certificates for a domain.
The preferred URL for a page, declared with link rel="canonical".
Public, append-only logs of every certificate issued by public authorities.
A DNS alias that points one name at another name.
A business that collects and sells personal information about people it has no direct relationship with.
A proxy running on cloud or hosting servers.
DomainKeys Identified Mail: cryptographic signatures on outgoing email.
A policy telling receivers what to do with mail that fails SPF and DKIM alignment.
The Domain Name System, which maps names like example.com to IP addresses and other records.
Cryptographic signatures that let resolvers verify DNS answers weren't tampered with.
Optimizing content so AI assistants find, trust and cite it.
Checking a business's Google Maps ranking from many points on a map grid.
A numeric customer ID for a Google Maps listing, usable in maps.google.com/?cid= links.
A stable text identifier Google uses for a business or place on Maps.
A real browser (like Chrome) running without a visible window, controlled by code.
Annotations that tell search engines which language or region each page version targets.
How often a word or phrase appears on a page relative to the total word count.
A Markdown file at /llms.txt that gives AI assistants a curated map of a site.
An open protocol that lets AI assistants call external tools and data sources.
A policy that forces encrypted (TLS) delivery of email to a domain.
A DNS record that tells the internet which servers accept email for a domain.
A DNS record naming the authoritative name servers for a domain.
Meta tags (og:title, og:image…) that control how links look when shared.
The Registration Data Access Protocol, the JSON-over-HTTPS successor to WHOIS.
A proxy that routes requests through consumer internet connections.
A file at the root of a site telling crawlers which paths they may fetch.
Search Engine Results Page: everything a search engine shows for a query.
The Start of Authority record with a zone's primary server, admin contact and timers.
Sender Policy Framework: a TXT record listing which servers may send email for a domain.
A certificate that proves a site's identity and enables HTTPS encryption.
Machine-readable facts about a page using the schema.org vocabulary.
How long, in seconds, resolvers may cache a DNS answer.
A DNS record holding free text, used for SPF, DMARC, domain verification and more.
Automatically collecting publicly available data from websites.
An HTTP callback a service sends to your URL when something happens.
The original plain-text protocol (port 43) for looking up who registered a domain.
A file listing a site's URLs so search engines can discover them.