You have sat in a meeting where somebody said "we will point the A record at the new host once the TTL has dropped". And you nodded, because asking would have meant starting the whole conversation again.
Here are those words back, in groups, because on their own they do not stick. They turn up when you commission a new site, when an old one moves, or when something breaks. Every abbreviation is written out in brackets: written out, most of them explain themselves. The words that sit in the quote itself, beside the designer's draft and in the yearly domain letter are on a second sheet.
The words that say where to find you
The first group is not about your site, it is about the road to it. Every time somebody types your address into a browser, one question runs in the background: where is this site actually? These words travel together, and they arrive in the week of a move.
- Domain - your address, for example
yourcompany.com. You do not buy it outright, you rent it by the year, and whose name that rental is in decides more than everything else on this list. - DNS (Domain Name System) - the system that translates an address into the location of a machine. Without it a domain is a label pointing nowhere.
- Nameserver - the place where that translation is kept. "Let us switch the nameservers" means control of your whole address moving to another house, and the mail goes with it.
- A record - one line inside that translation: this address points at this machine. A move is usually the changing of that one line.
- TTL (Time To Live) - how long the world is allowed to remember the old answer. That is why a move does not happen for everyone at once: you see the new site immediately, somebody elsewhere sees the old one for hours.
This group also produces the most expensive shock of moving day. Switching nameservers takes the email with it, and if the mailboxes are not ready at the new place first, messages do not arrive. A site comes back in a couple of minutes, a lost message never does.
The words that say where the site lives
An address is a label. Somewhere there has to be a machine that answers, and it is not in your cupboard. The second group is about that machine and the lock in front of it.

- Hosting - rented space on a server, the machine where your site's files sit. It is sold by the month like storage space, and what is in it is almost always the same: room, bandwidth, and somebody keeping an eye on the machine.
- SSL and HTTPS (Secure Sockets Layer, HyperText Transfer Protocol Secure) - the lock in the address bar. HTTPS is what the visitor sees, SSL is the technology behind it. Without it the browser writes "not secure" next to your site.
- Certificate - the file that proves the lock. It expires and usually renews itself. When one renewal fails, the site is behind a red warning in the morning.
The words about the inside of the site
The third group comes up when you want to change something yourself. Behind them is always the same question: can you manage it alone, or do you have to ring somebody.
- CMS (Content Management System) - the part you log into when you want to swap a piece of text or a photo. WordPress is one of them, not the only one.
- Plugin - an add-on bolted on afterwards: bookings, a form, a shop. Every plugin is somebody else's code inside your site, and every plugin has to be updated even when you never use it.
- Theme - the design layer on top of the content. "Let us change the theme" does not mean losing the content, but it does mean every page has to be checked afterwards.
- Cache - a copy of the page made in advance so things load faster. That is why you do not see your own change immediately, and why somebody eventually tells you to clear the cache.
The words that surface when something changes
The fourth group belongs to no particular week. It arrives when a site gets a new shape, a new address or a new person looking after it, and this is where things disappear quietly.

- Backup - yesterday's copy of your site, sitting somewhere else. Two questions give the word any meaning: how old is that copy, and has anybody ever put one back. An untried copy is a promise, not a backup.
- 301 redirect - a permanent sign saying "this page moved here". When addresses change, the old ones must not be deleted: those are the ones Google knows and the ones sitting in bookmarks.
The backup comes with proper upkeep anyway. The redirects are something somebody has to remember on the day of the move.
The words that sit on the invoice
The fifth group does not come from a meeting. These words sit on the hosting invoice and in the control panel, where nobody reads them out to you. The plans really are almost identical inside, and only the measurements differ. Those measurements say one thing: how much your site can take at once.
- Shared hosting - the same machine as a few hundred other sites, all of you sharing its power. For a small site that is a sensible choice, not the cheap option.
- VPS (Virtual Private Server) - your own slice of that machine, with processor and memory a neighbour cannot eat. The difference is a flat on a shared corridor and a floor of your own.
- Dedicated server - a whole machine for you alone, a house of your own. Most websites never get anywhere near needing one, and that is good news.
- Disk space - how many gigabytes your files take up: images, video, the database and the copies. Text will never fill it, photos uploaded straight off a phone will.
- Bandwidth - how much data goes out to visitors over a month. On a small site that number is usually so large that you never notice it.
- Processor and memory - how many visitors the site can serve at the same time. The real limit comes from here, not from the gigabytes.
- "Unlimited" - there is no such thing as unlimited hosting. The limit exists, it is simply written somewhere else: in the fair use clause. And it is usually about processor time or the number of files rather than gigabytes.
- Control panel (cPanel, Plesk, DirectAdmin) - the place you log into to see those limits for yourself. The numbers are in front of you there even when the invoice never mentions them.
- PHP version (Hypertext Preprocessor) - the version of the language your site runs on. When your supplier asks to update it, that is usually good news: a newer version is faster and still gets fixes, an old one does not.
And the part the sales page leaves out: most of these lines have nothing to do with a small website, and none of them make the invoice smaller. The only things worth knowing about that line are what happens when one of the limits is reached, and who updates PHP when the time comes. Everything else on that invoice is a measurement, not a decision.
The words that arrive on a report
The sixth group comes from neither a meeting nor an invoice. It arrives as a screenshot: somebody sends you red numbers, or a sentence saying the site "needs SEO". Almost everything here is an abbreviation, and being an abbreviation is the only reason any of it frightens anybody.
- SEO (Search Engine Optimization) - the work of being found in search. Not one button and not one month, but content, speed and the technical side kept in order at the same time.
- AEO (Answer Engine Optimization) - the same work for the answer an AI assistant gives without ever opening your site. We have a separate page about it.
- Indexing - whether Google has taken your site into its list at all. Before that, ranking is a pointless conversation: a page that is off the list is not in a bad position, it is simply absent.
- Sitemap and robots.txt - two files written for machines. The first is a list of your pages, the second says where a robot may not go. A robots.txt set wrongly by accident is the quietest way to disappear from search.
- Meta title and meta description - the two lines a person reads in the search results before clicking through to your site. They are written for that person, not for the robot.
- Core Web Vitals - the three numbers Google uses to measure whether a page feels fast to a human being. These are the ones that go red in a report.
- FCP (First Contentful Paint) - the moment the visitor sees the first thing on your page. Until then they are looking at a white screen.
- LCP (Largest Contentful Paint) - the moment the biggest thing on the screen, usually the header image, has arrived. This is what Google measures, and usually the number that is bad on your site.
- CLS (Cumulative Layout Shift) - how much the page moves under your nose while it loads. If you have ever tapped the wrong button because the page shifted, that number was bad.
- INP (Interaction to Next Paint) - how long the page thinks before your tap does anything.
- TTFB (Time To First Byte) - how long the server thinks before it sends anything at all. That number is about the hosting, not the design.
- PageSpeed Insights and Lighthouse - Google's free tools that produce those numbers, with one big score next to them. The score is a summary, not a grade.
- Search Console and GA4 (Google Analytics 4) - the first shows what Google knows about your site, the second what visitors do once they are on it. Both are free, and both have to be switched on by somebody.
And the part that never comes with the red screenshot: the score is not the site. A 60 does not mean the website is broken, and a 100 brings in no customers by itself. Two things in this group are genuinely your business. Whether the site is indexed, because without that no other number here means anything. And whether LCP arrives within a couple of seconds on a phone, because otherwise some visitors leave before they see anything at all. The rest of the abbreviations are your supplier's tools. If your site is not showing up in search, our free search engine audit starts from exactly these numbers.
You do not have to learn any of this
Now the part that made this worth reading. You do not need to master these words, only to ask one question back. It fits every word above:
"What changes for me once this is done, and what happens if we do not do it?"
The question translates the conversation into your language, and it shows whether the other side of the table has a plan or just a habit.
And then the thing nobody says in a sales call: most of these words cost you nothing even when they go wrong. A bad theme is ugly, a stuck cache is annoying. Three words are different.
- Domain. If it is in somebody else's name, the site is not yours, whoever paid for it.
- Backup. If there is none, or if one has never been put back, then one bad day is final.
- Nameserver on moving day, because of the mail. The only place here where an hour of carelessness costs you customers.
The rest is vocabulary. Ask about it when it lands in front of you, and do not study ahead.
One sentence is measurement enough
Every word here was explained in a sentence or two, with no diagram and no spaceship analogy. They really are that simple, which gives you the cheapest test you have on a supplier.
Ask about any word they have just used, and listen for whether the answer fits into one sentence. Somebody who knows the subject has one. Somebody who does not will either repeat the same word in different words, or explain why it cannot be explained. Try it on us as well.
The same goes for the invoice. Somebody who cannot tell you what an A record is usually cannot tell you what you are paying for on the fourth line either.
Our questions and answers are written out for the same reason, and if something here stayed unclear, just ask us. One word is a perfectly good question.
Frequently asked questions
A domain is the address, for example yourcompany.com, and you do not buy it outright, you rent it by the year. Hosting is rented space on a server where the site's files actually sit, sold by the month like storage space. The address is a label, the hosting is the house: the domain says where to look for you, the hosting is what answers when somebody arrives. Hosting can be changed while the address stays the same: a move is usually the changing of the one line that says which machine your domain points at. More important than the price of either is whose name the domain is in, because that decides whether the site is really yours.
TTL says how long the world is allowed to remember the old answer. A move changes the A record, the line saying which machine your address points at, but the old answer has already spread to many places. That is why you see the new site immediately while somebody elsewhere still sees the old one for hours. The same logic applies to email, where it matters more: if the nameservers are switched before the mailboxes are ready at the new place, messages do not arrive. A site comes back in a couple of minutes, a lost message never does.
No. You need to be able to ask one question back, and it fits every one of these words: "What changes for me once this is done, and what happens if we do not do it?" The question translates the conversation into your language and shows whether the other side has a plan or just a habit. Most of these words cost you nothing even when they go wrong: a bad theme is ugly and a stuck cache is annoying. The rest is vocabulary you can ask about when it lands in front of you.
Ask about any word they have just used and listen for whether the answer fits into one sentence. A domain, DNS, a certificate, a cache and a backup can all be explained in a sentence or two, with no diagram and no analogies. Somebody who knows the subject has that sentence. Somebody who does not will either repeat the same word in different words, or explain why it cannot be explained. The same goes for the invoice: somebody who cannot tell you what an A record is usually cannot tell you what you are paying for on the fourth line either.
No. There is no such thing as unlimited hosting: every machine is finite and every provider knows it. The limit exists even on an unlimited plan, it is simply written somewhere other than next to the price, usually in a fair use clause. And it is rarely about gigabytes. It is normally about processor time or the number of files, because those are what make a machine unusable for everybody else on it. For a small website this is neither a trick nor a problem, since a site like that rarely gets near any limit at all. Only one thing is worth knowing: what happens when the limit is reached.
On shared hosting your site sits on the same machine as a few hundred others, and all of you share its power. A VPS is your own slice of that machine: the processor and memory are set aside for you and a neighbour cannot eat them. A dedicated server is a whole machine for you alone. The difference is a flat on a shared corridor, a floor of your own, and a house of your own. Most websites live a full life on shared hosting, and a more expensive tier does not make a site faster by itself. Moving up is worth considering when the site slows down at busy hours, not when disk space runs out.
They are three of Google's Core Web Vitals, and written out they explain themselves. FCP is First Contentful Paint: the moment the visitor sees the first thing on your page, before which they are looking at a white screen. LCP is Largest Contentful Paint: the moment the biggest thing on the screen, usually the header image, has arrived. CLS is Cumulative Layout Shift: how much the page moves while it loads, which is why you have at some point tapped the wrong button. Of the three, the one that matters to you is mostly LCP, because if it does not arrive within a couple of seconds on a phone, some visitors leave before they see anything.
No. The score is not the site. A 60 does not mean the website is broken, and a 100 brings in no customers by itself: PageSpeed Insights and Lighthouse give you a summary, not a grade. Two things on that report are genuinely your business. The first is indexing, whether Google has taken your site into its list at all, because without that no other number means anything. The second is LCP on a phone, because that measures the moment a visitor actually sees the page. The remaining abbreviations are your supplier's tools, and fixing them is their job rather than your worry.
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