Hosting plans and support replies are full of jargon. This web hosting glossary explains the terms you will meet most often, grouped by topic, so you can compare plans and follow technical instructions with confidence.
Before you start
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Plans and resources
- Disk space (storage): total size of your files, databases and email.
- NVMe: a fast type of SSD storage connected directly over PCIe, much quicker than SATA drives.
- Bandwidth (data transfer): the amount of data sent from your site to visitors per month.
- Inodes: the number of files and folders in your account. Every file, email and cache file counts as one.
- CPU limit: the share of processor time your account may use, often shown as a percentage of one core.
- RAM (physical memory): memory available to your site's running processes.
- IOPS: input/output operations per second, a limit on how many disk reads and writes your account can do.
- I/O throughput: disk read/write speed, in MB/s.
- Entry processes (EP): the number of simultaneous PHP or CGI requests your account can run at once. Not the same as visitors.
- NPROC: total number of processes your account may run.
- Unmetered: no fixed transfer quota, but still subject to fair use and resource limits.
Hosting types
- Shared hosting: many accounts on one server, each with its own limits.
- Reseller hosting: a plan that lets you create and sell separate cPanel accounts to your own clients through WHM.
- Master reseller: a plan that lets you create reseller accounts, not just cPanel accounts.
- VPS: a virtual private server with dedicated resources and root access.
- Dedicated server: a whole physical server for one customer.
- Managed hosting: the provider handles server updates, security and support.
Software and panels
- cPanel: the control panel for a single hosting account: files, email, databases, domains.
- WHM: Web Host Manager, the admin panel above cPanel for resellers and server owners.
- CloudLinux: an operating system that isolates accounts and enforces resource limits so one site cannot slow down others.
- LiteSpeed: a high-performance web server compatible with Apache configuration, with built-in caching (LSCache).
- PHP version / PHP selector: the PHP version your site runs on, selectable per account.
- Softaculous: a one-click installer for WordPress and hundreds of other apps.
- JetBackup: backup software that lets you restore files, databases and email from cPanel.
- WHMCS: billing and automation software used by hosting companies and resellers.
Domains and DNS
- Registrar: the company you register a domain with. Registry: the operator of a TLD.
- Nameservers: the servers that hold your domain's DNS records.
- A / AAAA record: points a name to an IPv4 or IPv6 address.
- CNAME: makes one name an alias of another.
- MX record: tells the world which server receives email for the domain.
- TTL: how long resolvers cache a DNS record, in seconds.
- DNS propagation: the time until cached old DNS answers expire around the world.
- EPP code: the authorisation code needed to transfer a domain.
Security and reliability
- SSL/TLS certificate: enables HTTPS encryption. AutoSSL issues free certificates automatically in cPanel.
- Uptime: the percentage of time a service is available. SLA: the provider's written uptime promise.
- WAF: web application firewall that filters malicious requests.
- DDoS: an attack that floods a server with traffic to take it offline.
- 2FA: two-factor authentication, a second login step such as an app code.
- Dedicated IP: an IP address used by only one account.
- TTFB: time to first byte, how quickly the server starts responding.
Note: When a site shows Resource Limit Is Reached or 508 errors, it is usually hitting entry process or CPU limits, not running out of disk space.
Frequently asked questions
What is the difference between bandwidth and speed?
Bandwidth on hosting plans usually means monthly data transfer. Speed depends on server performance, network and distance.
Why do inodes matter if I have free disk space?
Because the inode limit counts files, not size. Thousands of tiny cache files or emails can reach it before the disk is full.
Are entry processes the same as visitors?
No. An entry process lasts only while a request is being processed, so a site with few entry processes can serve many visitors, especially with caching.