Last updated: 23 July 2026
The domain and hosting industry runs on jargon that gets thrown around as if everyone already knows it. This page is the plain-English version — real definitions with enough context to actually be useful, not one-line dictionary entries. Where we've written a full guide on a term, it's linked from the definition.
Domains & DNS
The human-readable address for a website or service — yourbusiness.com.au, for example — that stands in for the numeric IP address computers actually use to find each other online. You don't own a domain outright; you hold a registration for it, renewable for as long as you keep paying and keep meeting the registry's eligibility rules.
The accredited company you register and manage a domain through. The registrar handles the registration paperwork with the relevant registry (auDA for .au domains, for example), collects renewal payments, and is usually where you log in to change a domain's nameservers or contact details. Your registrar isn't necessarily the same company hosting your website.
The distributed lookup system that translates a domain name into the information the internet actually needs — which server to fetch a website from, which server handles email for the domain, and so on. We've written a full plain-English guide to the individual record types: DNS records explained.
A server that holds the authoritative DNS records for a domain. Whoever controls a domain's nameservers controls its DNS — where the website resolves to, where email gets delivered, everything. A common source of confusion is editing DNS records in a control panel that isn't actually where the domain's nameservers point; if a DNS change doesn't seem to take effect, this is the first thing worth checking.
The numeric address (like 203.0.113.10 for IPv4, or a longer format like 2001:db8::1 for the newer IPv6) that identifies a specific device or server on the internet. Domain names exist so people don't have to remember these.
An A record points a domain or subdomain directly at an IP address — it's how yourbusiness.com.au gets connected to your actual web server. A CNAME record is an alias that points at another domain name instead of an IP address directly, commonly used so that www.yourbusiness.com.au follows whatever the bare domain is pointed at automatically. Full detail, including the other record types (AAAA, TXT, NS, SOA): DNS records explained.
The DNS record that tells the rest of the internet which mail servers handle email for a domain. A wrong or missing MX record is one of the most common causes of email quietly stopping — often after a hosting move, when a new host's "default" MX records silently override the ones actually pointing at your real mail provider.
TTL (Time To Live) is how long, in seconds, a DNS record is allowed to be cached before it's looked up again. "Propagation" is the informal (and slightly misleading) name for the delay this causes — a DNS change is live immediately, but cached copies elsewhere on the internet don't know that until their TTL expires. Full explanation, plus how to check what's actually live and how to plan a low-drama migration: DNS TTL and propagation explained.
An ABN (Australian Business Number) or ACN (Australian Company Number) is the entity identifier that most .au domain registrations are legally required to be linked to and eligible against. It matters for domains specifically because auDA checks that this entity is still active at renewal time — a lapsed ABN or ACN can block a renewal outright. See your .au domain won't renew if your ABN has lapsed for the detail.
auDA is the organisation that administers the .au domain namespace, including .com.au, .net.au, .org.au, and the shorter direct .au. Each of these has its own eligibility rules, generally requiring a genuine connection to an Australian entity. Full breakdown: .au domain eligibility explained.
The window after a domain expires, unrenewed, during which the original registrant can typically still recover it — usually for a higher fee than a standard renewal. Exact lengths and costs vary by registry and registrar. After this window closes, the domain is released for anyone to register, with no way back. Full checklist for avoiding this altogether: domain renewal checklist.
Hosting & servers
The service of storing a website's files and serving them to visitors on request. "Hosting" is a broad umbrella covering everything from basic shared hosting to a fully dedicated server — the term alone doesn't tell you much about what you're actually getting, which is why the tiers below matter more than the word itself.
The most common web-based control panel used on shared hosting, letting you manage files, email accounts, databases, and basic DNS without needing command-line or server-administration skills. "cPanel hosting" has become shorthand for shared hosting generally, since it's the most widely used control panel for that tier. Full comparison against the next tier up: cPanel hosting vs VPS.
A virtualised slice of a physical server with resources — CPU, RAM, storage — guaranteed to you and not shared with other customers, along with full root access. It sits between shared hosting and a dedicated server: more control and guaranteed resources than shared hosting, without the cost of an entire dedicated machine. See shared hosting vs VPS vs dedicated for how to decide between the three tiers, or cPanel vs VPS for the detailed shared-vs-VPS breakdown specifically.
An entire physical server allocated to a single customer, with no virtualisation layer and no other tenants at all. It's the highest tier of hosting, reserved for workloads with heavy resource demands or specific compliance requirements that rule out shared or virtualised infrastructure. See shared hosting vs VPS vs dedicated.
The percentage of time a server or service is actually available and working, usually quoted over a month or year (e.g. "99.9% uptime"). It's worth knowing that even a headline figure like 99.9% still allows for a real amount of downtime over a year — roughly 8–9 hours — so uptime numbers are a useful comparison tool but not a promise of zero disruption.
A stored copy of a website's files and database, kept separately so the site can be restored if something goes wrong — a bad update, a hacked site, accidental deletion, or a failed migration. The two things worth actually checking, rather than assuming: how far back your backups go, and whether you've ever actually tested restoring from one.
Security & email
The certificate that enables HTTPS on a website and proves, cryptographically, that traffic between a visitor's browser and the server is encrypted and that the server is who it claims to be. "SSL" is the older, still commonly used name for what is technically now TLS. Certificate lifespans are getting shorter industry-wide, which makes automated renewal increasingly important — see SSL certificate lifespans are shrinking.
The encrypted version of HTTP, the protocol web browsers use to load websites. It requires an SSL/TLS certificate to work. Browsers now flag plain HTTP sites as "not secure", and HTTPS is effectively mandatory for any site handling forms, logins, or payment details — and a baseline expectation for any site at all.
A DNS TXT record that lists which mail servers are allowed to send email on behalf of a domain. It's one of the three email-authentication records that help stop spammers forging email that appears to come from your business. Full setup guide: SPF, DKIM and DMARC explained.
An email-authentication method that attaches a cryptographic signature to outgoing mail, letting receiving mail servers verify the message genuinely came from your domain and wasn't altered in transit. Works alongside SPF and DMARC — see SPF, DKIM and DMARC explained.
The policy layer that sits on top of SPF and DKIM, telling receiving mail servers what to do with messages that fail those checks — deliver anyway, quarantine, or reject — and optionally sending you reports on who's sending mail claiming to be from your domain. It's usually the last of the three to set up, and the one that actually gives you enforcement rather than just a signal. Full guide: SPF, DKIM and DMARC explained.
A system that controls what network traffic is allowed to reach a server, blocking everything else by default. On a VPS or dedicated server this is something you (or whoever manages the server) is responsible for configuring; on shared hosting, it's handled for you as part of the platform.
Software designed to damage, disrupt, or gain unauthorised access to a system — a broad umbrella covering viruses, ransomware, and the scripts attackers plant on compromised websites. On a website specifically, malware often arrives through an outdated plugin, theme, or CMS core rather than anything a visitor did.
A scam where an attacker impersonates a trusted contact — often by compromising or closely spoofing a real email account — to redirect a payment or extract sensitive information. It typically involves no malware or hacking skill at all, which is part of why it's so effective. Full breakdown of how it actually plays out: Business Email Compromise: what it actually looks like.
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