Hosting glossary
Anyone buying or moving hosting runs into an MX record, a TTL and a transfer code within five minutes. Below, every term is explained in one sentence, without you having to look up another term first.
37 terms, grouped from the foundations to the detail. Where a page goes deeper, the link is there.
Hosting & servers
Web hosting #
Web hosting means renting space on a server that is permanently connected to the internet, so your website stays reachable for visitors.
Hosting is separate from your domain name: the domain is the address, the hosting is the building the site sits in. You can have both with the same provider, but you do not have to.
More on this →Shared hosting #
On shared hosting, several websites sit on one server and share its memory, processing power and disk.
Because the cost of that server is spread across all those sites, this is the cheapest way to put a website online. You only manage your own space.
More on this →VPS #
A VPS (virtual private server) is a partitioned server inside a larger machine, with dedicated resources of its own and root access.
You share the physical machine but not the capacity: the memory and processor cores are assigned to you. On a managed VPS the provider takes care of server administration.
More on this →Dedicated server #
A dedicated server is a complete physical machine that only you use, with no other customers running on it.
More on this →Colocation #
With colocation you place your own server in a provider's data center, which supplies rack space, power, cooling and connectivity.
The hardware stays yours, and so does managing it. The difference with a dedicated server is who owns the machine.
More on this →Control panel #
A control panel is the web interface through which you manage your hosting: mailboxes, databases, files, DNS settings and the PHP version.
At WWW4 that is Interworx. Which panel you get decides how you manage those things, not how fast your site is.
Uptime #
Uptime is the percentage of time a service is reachable, measured over an agreed period.
The decimals matter: 99.9% allows around 43 minutes of downtime a month, 99.99% around four minutes.
SLA #
An SLA (service level agreement) sets out in writing what availability, response times and support you may expect.
When comparing, look at what the SLA actually covers: the provider's network and hardware, or also the application you run on it yourself.
More on this →Domain names & DNS
Domain name #
A domain name is the address at which your website and email are reachable, for example yourcompany.be.
You do not buy a domain name, you rent it for a period — usually a year. If it expires without renewal, the name becomes available again after a grace period.
More on this →Extension (TLD) #
The extension is the last part of a domain name, such as .be, .com or .eu, and determines which registry the name falls under.
Every extension has its own registry that sets the wholesale price and the rules. That is why prices differ so widely between extensions.
More on this →Registrar #
A registrar is the party that registers domain names with the registry of an extension and with whom your domain name is held.
Your registrar is not necessarily your hosting provider: you can leave your domain name elsewhere and simply point the DNS at your host.
Nameserver #
Nameservers are the servers that decide which DNS data applies to your domain; they have the final say over where your site and mail live.
Changing nameservers moves the entire DNS management of your domain — including your email. So carry your records over first.
More on this →DNS record #
A DNS record is a single line in a domain name's zone that says where a particular kind of traffic should go.
More on this →A record #
An A record points a domain name or subdomain at the IP address of a server.
The variant for the newer address format is called AAAA. This is the record you change when your website moves to another server.
CNAME #
A CNAME record points one name at another name instead of at an IP address.
Handy for subdomains that an external service manages itself. On the bare domain name, without www, a CNAME is usually not possible.
MX record #
An MX record decides which mail server email for a domain name is sent to.
This is entirely separate from where your website runs: you can move your site without touching your mail, as long as you leave this record alone.
TXT record #
A TXT record holds free text in the DNS zone and is used in practice for SPF, DKIM, DMARC and domain verification.
TTL #
The TTL (time to live) is how long the rest of the internet may remember a DNS answer before asking again.
Lower the TTL a few days before a planned move: the switch then takes minutes instead of hours.
Propagation #
Propagation is the period in which a DNS change spreads across the internet and does not yet give the same answer everywhere.
Expect a few hours up to 48 hours, depending on the TTL your records carried and on your visitor's provider.
Transfer code (EPP) #
A transfer code, also called an EPP or auth code, is the password proving you are allowed to move a domain name to another registrar.
More on this →Whois #
Whois is the public lookup that shows whether a domain name is taken, which registrar holds it and when it expires.
Website technology
Disk space #
Disk space is the storage in your hosting plan, holding your files, images, databases and mailboxes together.
What usually fills a plan up is not the site files but old backups, log files and mailboxes with years of attachments.
Database #
A database stores your website's content — pages, products, users — separately from the files of your site.
Every common CMS needs at least one. When moving, you therefore have to take both the files and the database with you.
PHP #
PHP is the language most websites and content management systems run on; its version affects how fast and how secure your site is.
A PHP version that is too old no longer receives security updates. Pick the highest version your CMS and extensions support.
More on this →Cache #
A cache stores the result of work already done, so the next visitor does not have to have it calculated again.
Caching makes a site faster, but also means you sometimes do not see a change straight away. Clear the cache before concluding something is broken.
FTP and SFTP #
FTP and SFTP are protocols for copying files to your web space; the S variant does so encrypted.
Use SFTP where you can: with plain FTP your username and password travel in readable form.
Cron #
A cron job is a task the server runs automatically at fixed times, without anyone having to open a page.
Content management systems use cron for search indexing, cleanup and update notices. If cron stalls, a site degrades gradually without a clear error.
Security & continuity
SSL/TLS #
An SSL/TLS certificate encrypts the traffic between the visitor and your server, making your site reachable over https.
Without a certificate, browsers mark your pages as not secure. TLS is technically the successor to SSL; in practice the old name is still used.
More on this →Mixed content #
Mixed content is a page that loads over https itself but still fetches parts over http, which makes the browser warn anyway.
This is the most common cause of a "not secure" message despite a valid certificate. It usually sits in a hard-coded link in a theme.
DDoS #
A DDoS attack floods a server with traffic from many sources at once, until real visitors can no longer get through.
More on this →Backup #
A backup is a copy of your files and database at another point in time, so you can return to how your site was then.
A backup that has never been restored is an assumption, not a certainty. Test one once, certainly for a site your business depends on.
More on this →Restore #
A restore puts an earlier backup back in place; everything added after that moment is lost in the process.
The most important detail in a restore request is not what went wrong, but when it was still working.
Email with your hosting
Mailbox #
A mailbox is an inbox with its own address and password in which email for that address is stored.
More on this →Alias #
An alias is an email address without an inbox of its own: messages sent to it arrive in an existing mailbox.
Handy for role addresses such as info@ or billing@. Sending from an alias is not possible — that needs a real mailbox.
More on this →IMAP #
With IMAP your email stays on the server and your mailbox looks the same on all your devices.
POP3 #
With POP3 your device downloads email from the server and usually deletes it there, after which it no longer appears on other devices.
Mail collected locally is no longer on the server and therefore no longer in a later backup either.
SMTP #
SMTP is the protocol email is sent with, as opposed to IMAP and POP3 which retrieve mail.
For newsletters or automated shop mail, an SMTP relay is a better route than the mail function of your web hosting.
Further reading
If you know the terms and want to know what they mean together, these are the logical next steps.
