Hosting comes with a lot of jargon. This glossary explains the terms you’ll meet when choosing, setting up and running a VPS, in plain English, with links to deeper guides.

Servers and virtualization

  • VPS (virtual private server): a virtual machine with its own OS, resources and root access, running on a physical host. See what is a VPS.
  • Dedicated server: a whole physical server for one customer. See VPS vs dedicated server.
  • Hypervisor: software that runs virtual machines (KVM, Xen, Hyper-V, VMware).
  • KVM: the Linux kernel’s hypervisor; each VM has its own kernel. See what is KVM virtualization.
  • OpenVZ / LXC: container-based virtualization with a shared kernel. See KVM vs OpenVZ vs LXC.
  • vCPU: a virtual CPU core assigned to a VM. See vCPU explained.
  • Steal time: CPU time your VM wanted but the host gave to others.
  • Container: an isolated process environment (Docker, Podman) sharing the host’s kernel. See Docker vs virtual machine.

Resources

  • RAM: working memory for running programs. See how much RAM a VPS needs.
  • Swap: disk space used as overflow memory (slow).
  • SSD / NVMe / HDD: storage types; SSDs are much faster than HDDs.
  • IOPS: input/output operations per second, a storage speed measure.
  • RAID: combining disks for redundancy and/or speed (RAID 1, 10…). Not a backup.
  • Inode: filesystem entry per file; you can run out with many small files.

Network

  • Bandwidth / transfer: data volume moved per month (e.g. TB/month). See bandwidth vs traffic vs speed.
  • Port speed: maximum rate of the network connection (e.g. 1 Gbps).
  • Unmetered: no monthly transfer cap, usually at a fixed rate (Mbps).
  • Latency / ping: round-trip time between two points. See latency vs bandwidth.
  • Packet loss: packets that never arrive; causes lag and retransmits.
  • BGP: the routing protocol between networks; “BGP multi-line” means several upstream carriers.
  • CN2 / CN2 GIA: China Telecom’s premium international backbone; GIA is the top tier with optimised routing to mainland China. See CN2 GIA explained.
  • IPv4 / IPv6: internet address formats. See VPS IP addresses.
  • Dedicated IP: an IP used only by you. See dedicated IP benefits.
  • PTR / rDNS: reverse DNS, mapping an IP to a hostname (important for email).
  • NAT: sharing one public IP among many private addresses.
  • Firewall: rules controlling allowed traffic (UFW, nftables, iptables). See UFW.
  • DDoS: distributed denial-of-service attack. See VPS DDoS protection.

DNS and domains

  • DNS: the system translating names to IPs. See DNS records explained.
  • A / AAAA record: name → IPv4 / IPv6 address.
  • CNAME: alias from one name to another.
  • MX record: where a domain’s email is delivered.
  • TXT record: text data; used for SPF, DKIM, DMARC, verification.
  • TTL: how long DNS answers are cached. See DNS propagation.
  • Nameservers: the servers authoritative for a domain’s DNS.

Access and administration

  • Root: the all-powerful Linux admin account. See VPS root access.
  • sudo: run a command with admin rights as a normal user.
  • SSH: encrypted remote terminal access. See SSH keys.
  • SFTP: file transfer over SSH.
  • RDP: Remote Desktop Protocol for Windows servers.
  • VNC console: out-of-band screen access from the control panel. See VPS VNC console.
  • Control panel: web UI for managing servers or websites (cPanel, HestiaCP…). See cPanel alternatives.
  • Managed / unmanaged: whether the provider administers the OS for you. See managed vs unmanaged VPS.

Web hosting stack

  • LEMP / LAMP: Linux + Nginx/Apache + MySQL + PHP. See install a LAMP stack.
  • Reverse proxy: a server in front of apps forwarding requests (Nginx, Caddy, Traefik). See Nginx reverse proxy.
  • Load balancer: distributes traffic across servers. See load balancer types.
  • SSL/TLS certificate: enables HTTPS; free from Let’s Encrypt. See Let’s Encrypt.
  • CDN: network of edge servers caching your content near users. See CDN for websites.
  • PHP-FPM: PHP process manager used with Nginx. See Nginx with PHP-FPM.
  • Object cache: in-memory cache for app data (Redis, Memcached).
  • TTFB: time to first byte, a server responsiveness metric.

Reliability and operations

  • Uptime / SLA: availability percentage / the provider’s commitment. See VPS uptime and SLAs.
  • Backup / 3-2-1 rule: copies of data, with one off-site. See backup strategy.
  • RTO / RPO: acceptable downtime / acceptable data loss.
  • Monitoring: tracking metrics and alerts. See uptime monitoring tools.
  • Vertical / horizontal scaling: bigger server / more servers. See VPS scaling.
  • Cron: Linux task scheduler. See crontab.
  • systemd: Linux service manager. See systemctl commands.

Email

  • SMTP: the protocol for sending mail; ports 25, 465, 587. See SMTP ports.
  • SPF / DKIM / DMARC: email authentication records. See SPF, DKIM and DMARC.
  • MTA: mail transfer agent (Postfix, Exim).

Related: self-hosting for beginners and VPS hosting costs.

  • VPS Guide
  • Beginners
  • Glossary