Skip to main content
Quick, no-jargon definitions of the terms used throughout the Opus Host docs.

​
A

AUP (Acceptable Use Policy). The rules for what you can and cannot do on your VPS. See Acceptable Use. apt. The package manager on Debian and Ubuntu. Used to install and update software (apt install nginx).

​
B

Backup. A copy of your VPS disk you can restore later. See Backups & Snapshots. Bandwidth. The amount of network traffic your VPS can transfer in a given period.

​
C

cron. The classic Unix job scheduler. See Cron Jobs. CLI (Command-Line Interface). The text-based way of controlling your VPS. What you use over SSH.

​
D

Daemon. A background process. Most services on a VPS run as daemons managed by systemd. DNS (Domain Name System). The system that turns example.com into an IP address. See Custom Domain. Docker. A tool for running apps in isolated containers. See Docker.

​
F

Firewall. A filter that decides which network traffic is allowed in and out. On Opus Host VPS this is usually UFW. See Firewall.

​
H

Hostname. The name of your VPS on the network (e.g. myserver). HTTPS. HTTP with encryption. Enabled by installing a TLS certificate, usually from Let’s Encrypt.

​
I

IP address. The numeric address of your VPS on the internet.

​
N

Nginx. A popular web server and reverse proxy. See Web Server and Nginx Reverse Proxy.

​
P

Package. A piece of software installable through apt. Port. A number that identifies a specific service on your VPS. Web servers use 80/443, SSH uses 22. See Port Reference. PM2. A process manager for Node.js apps. See Node.js & PM2.

​
R

Reboot. Restart the VPS. See Power Controls. Reverse proxy. A server (usually Nginx) that sits in front of your apps and forwards requests to them. root. The all-powerful admin user on Linux. Avoid using it directly; create a sudo user instead. See User Management.

​
S

SSH (Secure Shell). The standard way to get a remote command line on your VPS. See SSH Access. SSH key. A cryptographic key pair used to log in over SSH without a password. Safer and faster. sudo. “Superuser do”. Runs a single command as root without switching users. Swap. Disk space Linux uses as overflow memory when RAM is full. See Swap & Performance. systemd. The service manager on modern Linux. Starts, stops, and supervises daemons. See systemd Services.

​
T

TLS/SSL. The encryption behind HTTPS. Certificates from Let’s Encrypt are free.

​
U

UFW (Uncomplicated Firewall). A user-friendly frontend for the Linux firewall. See Firewall. Uptime. How long your VPS has been running since the last reboot (uptime command).

​
V

VPS (Virtual Private Server). A virtual computer running on shared hardware, but with its own OS, files, and IP address. What Opus Host gives you.

​
W

Web server. Software that serves websites over HTTP/HTTPS. Nginx and Apache are the most common.