Log into your domain control panel and you're immediately confronted with a wall of acronyms — A records, CNAMEs, TTL, nameservers, MX, SPF, DKIM — with no explanation of what any of them do or what happens if you get one wrong. Most small business owners never need to touch this panel at all, but when they do, it's usually mid-crisis. Here's what the words actually mean, in an order that makes sense.
Registrar, host and nameservers — the three different things people confuse
You can buy a domain from one company, point its nameservers at a completely different DNS provider, and host the actual website with a third company entirely. In practice most small businesses keep things simpler than that, but understanding the split matters the moment you want to move hosting, add email, or diagnose why something's broken. We cover the domain side of this in more detail in how to choose a domain name.
The DNS records that actually matter
- A record — points your domain to a server's IPv4 address (a string of numbers like 192.0.2.1). This is what makes yoursite.co.uk load your website.
- AAAA record — the same idea, for the newer IPv6 address format.
- CNAME record — points one domain or subdomain to another domain name rather than a raw IP address. Commonly used for things like www pointing at your main domain, or third-party tools like email platforms.
- MX record — Mail Exchange. Tells the internet which server handles incoming email for your domain. This is completely separate from your website's A record, which is exactly why moving hosting can quietly break email if it's overlooked.
- TXT record — a free-text field used for verification and security purposes, most commonly SPF and DKIM.
- SPF — a type of TXT record listing which servers are allowed to send email on behalf of your domain, helping prevent it being used for spam or impersonation.
- DKIM — another authentication method, using a cryptographic signature to prove an email genuinely came from your domain and wasn't tampered with in transit.
Get SPF or DKIM wrong and legitimate emails from your business can start landing in spam folders, or fail to send at all — a quiet, easy-to-miss problem that costs real enquiries.
TTL and propagation — why changes don't happen instantly
"Propagation" is simply that spreading process — different servers and internet providers around the world updating their cached copy of your DNS records at slightly different times. Most changes are visible within minutes to a few hours; occasionally a handful of stragglers take up to 48 hours to catch up. If you're planning a change with any risk attached — moving hosting, switching nameservers — it's worth lowering the TTL a day or two in advance so the eventual change takes effect faster.
SSL certificates, in plain terms
Certificates are issued for a domain (or set of domains) and need to be kept valid and correctly installed on the server — an expired or misconfigured certificate throws browser warnings that will scare off visitors instantly. Free, automatically renewing certificates are standard practice now, and any competent hosting setup should include one without it being sold as a premium add-on. We go into why this matters more broadly in is your website secure.
Redirects and the www vs non-www question
The fix is a permanent (301) redirect from whichever version you don't use to the one you do, set up once at server or DNS level and then left alone. The same logic applies to old pages that have moved or been removed — a proper redirect preserves any value built up at the old address rather than sending visitors and search engines to a dead end.
What you should never touch without a plan
- Changing nameservers without confirming every existing DNS record has first been copied across to the new provider.
- Editing or deleting MX records without checking they're not needed for live email.
- Letting a domain registration lapse — once it expires, someone else can register it, and getting it back is difficult to impossible.
- Changing an A record for a domain that's actively receiving traffic, without a plan for how long the old and new servers both need to keep working during propagation.
If in doubt, the safe approach is always: note down every existing record before changing anything, make the change during a quiet period, and keep the old service running until you've confirmed the new one is fully working.
What we handle on a managed plan
Common questions
What's the difference between a domain and hosting?
The domain is the address; hosting is the building it points to. You can move hosting without changing the domain, and change the domain while keeping the same hosting.
What are nameservers?
Nameservers decide which company answers DNS questions about your domain. Whoever controls the nameservers controls where your website and email traffic go, which is why they should never be changed casually.
How long does DNS propagation take?
Usually minutes to a few hours, occasionally up to 48 hours for the last stragglers. The delay depends on the TTL set on the record before the change was made.
Will changing hosting break my email?
It can, if the MX records aren't carried across. Website records (A and CNAME) and email records (MX, SPF, DKIM) are separate, and moving one without the other is the most common way business email goes down mid-migration.
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Our managed plans handle the domain, SSL, updates, backups and edits so you never have to think about it. Free, no-pressure chat — usually within a day.
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Written by Adam, A9 Web Design
Adam builds hand-coded websites for small businesses across Cambridgeshire and looks after their hosting, SEO and advertising day to day. Everything here comes from work on real client sites — no theory, no filler.