Hosting glossary

A DNS record that points a name to an IPv4 address, telling browsers which server a website is on.

A DNS record that points a name to an IPv6 address. The IPv6 equivalent of an A record.

Widely used web server software that answers browser requests and reads .htaccess files for per-folder rules.

A nameserver that holds the real DNS records for a domain, rather than a cached copy.

An automatic reply sent to anyone who emails a particular address.

A copy of website files, databases and email kept so they can be restored if something goes wrong. Most useful when stored away from the hosting account.

The amount of data sent from your hosting to visitors in a month. Strictly called data transfer.

A message returned to the sender explaining why an email couldn’t be delivered.

Automated attempts to guess a login by trying many passwords.

A DNS record listing which certificate authorities may issue SSL certificates for a domain.

A stored copy of something — a page, a file, a DNS answer — reused to save time.

An email setting that accepts mail sent to any address at a domain, even addresses that don’t exist. Attracts large amounts of spam.

Content delivery network: servers around the world that deliver copies of a site’s files from locations near each visitor.

An organisation trusted by browsers to issue SSL certificates, such as Let’s Encrypt.

Traxio’s account portal for billing, invoices, payment methods and cancelling.

Content management system: software such as WordPress for editing a website through an admin screen.

A DNS record that makes one name an alias of another name.

The dependency manager for PHP, which downloads the libraries a project needs into a vendor folder.

A web interface for managing a hosting account without the command line. Traxio uses DirectAdmin.

Google’s measures of real-world page experience: LCP, INP and CLS.

The processor. On shared hosting, each account can use a limited share of CPU time.

A command scheduled to run automatically at set times.

Certificate signing request: data submitted to a certificate authority when requesting a paid SSL certificate.

An organised store of information, such as posts, users and orders, used by a website.

Distributed denial of service: overwhelming a site or server with traffic from many sources.

A physical server used by a single customer.

The hosting control panel used by Traxio for files, email, databases, DNS, SSL and more.

DomainKeys Identified Mail: a digital signature added to outgoing email and checked against a key published in DNS.

A DNS policy telling receiving servers what to do with email that fails SPF and DKIM alignment, and where to send reports.

Domain Name System: the internet’s directory that turns domain names into IP addresses and other information.

Traxio’s automatic check, during an account’s first 30 days, that its domain points to Traxio. Accounts whose domain hasn’t pointed here for 24 hours in a row can be suspended until it does, then restore automatically.

The time it takes for cached DNS answers around the world to expire and pick up a change.

Extensions that sign DNS records so resolvers can detect forged answers.

The folder a domain’s website is served from. On Traxio, the domain’s public_html folder.

A human-friendly website address, such as yourdomain.co.uk, rented from a registrar.

A company you register domain names with, and where nameservers are set.

The number of simultaneous connections running scripts on a shared hosting account.

A file recording errors from the web server and PHP, used to diagnose problems.

DirectAdmin’s browser-based tool for uploading, editing and organising files.

Settings controlling who can read, write and execute a file, written as numbers such as 644 and 755.

An email address that passes messages on to another address without storing them.

File Transfer Protocol: a way to move files to and from a server. Use it with TLS encryption.

FTP with TLS encryption added.

A version control system for tracking changes to code.

A file on your computer that overrides DNS for specific names, useful for previewing a site before changing DNS.

HTTP Strict Transport Security: a header telling browsers to use HTTPS only for a site.

A configuration file that sets web server rules — redirects, access control, caching — for a folder and its subfolders.

Hypertext Transfer Protocol: how browsers and web servers exchange pages. Unencrypted.

A three-digit number a server returns with each response, such as 200 OK, 301 moved, 404 not found or 500 server error.

HTTP encrypted with TLS, shown by a padlock in the browser.

Input/output: reading from and writing to disk. Shared hosting may limit I/O speed per account.

A protocol for reading email that keeps messages on the server, in sync across devices.

A filesystem record for one file or folder. Inode usage counts how many files you have.

The numeric address of a device on the internet, such as 203.0.113.10 (IPv4) or 2001:db8::10 (IPv6).

A non-profit certificate authority providing the free SSL certificates used on Traxio.

A web server compatible with Apache configuration, often paired with its LSCache caching system.

LiteSpeed’s server-level page caching system, used through plugins such as LiteSpeed Cache for WordPress.

Malicious software. On websites, usually injected code that redirects visitors, sends spam or steals data.

An open-source database that began as a fork of MySQL and is compatible with it.

The maximum memory a single PHP request may use.

Insecure http:// resources loaded on an https:// page.

A DNS record naming the server that receives email for a domain.

A widely used relational database for websites.

A server that holds a domain’s DNS records. Set at the registrar.

A fast storage technology for solid-state drives, used for Traxio’s disk space.

A saved copy of a finished web page served to later visitors without rebuilding it.

A domain showing a placeholder page, usually from the registrar, rather than a real website.

The permanent URL structure for posts and pages, especially in WordPress.

Fake messages or pages designed to steal passwords or payment details.

A server-side programming language that powers WordPress and most hosting applications.

An add-on module giving PHP extra capabilities, such as image processing or database access.

A browser tool for managing MySQL and MariaDB databases.

An add-on that extends an application such as WordPress.

A protocol for downloading email to a single device, usually removing it from the server.

A numbered channel on a server for a particular service, such as 443 for HTTPS or 993 for IMAP.

A database query where values are sent separately from the SQL, preventing SQL injection.

A reverse DNS record mapping an IP address back to a hostname. Controlled by the IP’s owner.

The folder whose contents are served as your website.

A DNS server that looks up answers on your behalf and caches them.

An instruction sending a visitor from one URL to another. 301 is permanent, 302 temporary.

An in-memory data store often used as an object cache for applications such as WordPress.

Full administrative control of a server’s operating system, not available on shared hosting.

The webmail application used to read Traxio email in a browser.

SSH File Transfer Protocol: encrypted file transfer over a single connection.

Hosting where many isolated accounts share one server’s resources.

Simple Mail Transfer Protocol: the protocol used to send email.

A one-click installer for WordPress and hundreds of other web applications.

Sender Policy Framework: a DNS TXT record listing servers allowed to send email for a domain.

An attack that inserts malicious SQL through unvalidated input.

A DNS record naming the host and port for a specific service.

Secure Shell: an encrypted way to log in to a server’s command line. On Traxio it uses port 26628.

A file that proves a website’s identity and enables encrypted HTTPS connections. Modern certificates use TLS.

A private copy of a website used to test changes before applying them to the live site.

A command that upgrades a plain connection to an encrypted one, used on port 587 for email.

A name under your domain, such as blog.yourdomain.co.uk, which can host a separate site.

A package controlling a CMS site’s design and layout.

Top-level domain: the last part of a domain, such as .uk, .com or .org.

Transport Layer Security: the encryption protocol behind HTTPS and secure email, successor to SSL.

Time to first byte: how long a server takes to start sending a response.

Time to live: how long a DNS answer may be cached, in seconds.

A DNS record holding text, used for SPF, DKIM, DMARC and domain verification.

The proportion of time a website or server is available.

Virtual private server: a virtual machine with reserved resources and full operating-system control.

Software that receives requests from browsers and returns pages and files.

Reading and sending email in a web browser instead of an app.

A modern image format producing smaller files than JPEG or PNG.

A lookup showing a domain’s registration details, including nameservers and expiry date.

An SSL certificate covering every subdomain of a domain, such as *.yourdomain.co.uk.

Free, open-source website software; the most widely used CMS.

WordPress’s built-in scheduler, which runs due tasks when pages are visited.

A conventional subdomain for websites. yourdomain.co.uk and www.yourdomain.co.uk are separate names.