Glossary

What this is

Short, plain-English explanations for terms we use on the site and in emails. If something isn’t here, ask and we’ll add it.

DNS: The system that turns names (example.com) into IP addresses. Why it matters: every change (mail, web, records) depends on DNS being clean.
A/AAAA: Records that point a name to an IPv4 (A) or IPv6 (AAAA) address. Why it matters: where your site actually lives.
CNAME: Alias from one name to another (not at the apex). Why it matters: reduces duplication when a service moves.
MX: Mail exchange destination for your domain. Why it matters: where inbound email goes.
TXT: Free-form text record. Why it matters: used for SPF, DKIM, DMARC, verification.
TTL: How long resolvers cache a record. Why it matters: lower TTL before cutover so changes land faster.
Propagation: Resolvers updating after a change. Why it matters: some users will see old data until caches expire.
Registrar: Where you register/renew the domain name. Why it matters: controls ownership and transfer.
Nameservers: Servers that host your DNS zone. Why it matters: moving these hands DNS control to someone else.
Anycast: One IP address announced from multiple locations worldwide. Why it matters: DNS queries are answered by the nearest healthy point of presence, which lowers latency and adds resilience if a location fails.
DNSSEC: Signing DNS so records can’t be spoofed. Why it matters: protects mail/web from poisoned lookups.
PTR (reverse DNS): Maps IP → name. Why it matters: essential for mail deliverability; some hosts check it.

SPF: List of servers allowed to send mail for your domain. Why it matters: helps receivers trust your mail.
DKIM: Cryptographic signature added to outgoing mail. Why it matters: proves the message wasn’t altered.
DMARC: Policy telling receivers what to do if SPF/DKIM fail; can send you reports. Why it matters: reduces spoofing, improves trust.
ARC: Auth results preserved across forwards. Why it matters: keeps auth intact through mailing lists/forwarders.
IMAP: Mail protocol for reading/syncing mail across devices. Why it matters: keeps mailboxes in sync.
SMTP / Submission: How mail is sent. Why it matters: Submission (usually port 587) is the authenticated path for users.
Autodiscover: Service that helps clients auto-configure. Why it matters: makes Outlook/Apple Mail setup simpler.

TLS / HTTPS: Encryption for websites. Why it matters: privacy, integrity, and modern browser requirements.
HSTS: Policy forcing HTTPS. Why it matters: prevents downgrade to insecure HTTP.
CDN: Edge servers that cache content closer to users. Why it matters: faster global delivery (optional).
Caching: Storing copies to serve faster. Why it matters: major speed wins when tuned correctly.
Cutover: The moment traffic switches from old to new. Why it matters: plan, verify, and have rollback ready.

Staging: A safe copy of your site for testing changes. Why it matters: catch issues before going live.
Pilot: A small, low-risk subset moved first to prove the plan and surface issues. Why it matters: catches surprises before full cutover.
Content freeze: A short period where content changes are paused during final sync and cutover. Why it matters: prevents loss of edits while moving.
Smoke test: Basic checks after a deploy or migration (pages load, forms submit, emails send, errors aren’t piling up). Why it matters: catches obvious issues fast before deeper checks.
Rollback: Returning to a known good state. Why it matters: reduces risk when deploying or migrating.
Backups: Copies of data you can restore. Why it matters: last line of defence; we also test restores.
Monitoring: Watching key signals (uptime, errors, load). Why it matters: early warning beats outages.
TTL discipline: Lowering/raising TTL around changes. Why it matters: faster switches; fewer surprises.

2-step verification / MFA: Second factor at login. Why it matters: blocks most account takeovers.
Roles: Permissions groups for admins/users. Why it matters: keeps powerful actions limited.
Conditional Access: Rules about where/how accounts can sign in. Why it matters: balances security with usability.
Shared drives / SharePoint: Team storage with shared ownership. Why it matters: clearer access than personal folders.

DSN / NDR: Delivery Status Notification — a delivery report from the mail system showing success, delay, or failure. Why it matters: it includes SMTP status codes and reasons, making issues faster to diagnose and fix.

We keep definitions short on purpose. If you want the long version, ask and we’ll explain it in the context of your setup.