Linux, Servers & Web Hosting

Time-based job scheduler

A Unix-like scheduling system that runs commands automatically at specified times or repeating calendar intervals.

Run a command with another user's privileges

A command that lets an authorised user perform a specific task with elevated privileges, commonly as the root user.

Web server and reverse proxy

Software that serves web content and can also route requests as a reverse proxy, load balancer or gateway.

Uncomplicated Firewall

A command-line tool that simplifies creating and managing Linux firewall rules, especially on Ubuntu systems.

Secure Shell

An encrypted protocol used to sign in to remote machines, run commands and transfer data securely over a network.

Time a service remains available

The period a machine or service has remained running and available; often reported as a percentage over time.

Highest-privilege system account

The administrative account on a Unix-like system, normally able to read, change or remove almost anything.

Virtual Private Server

An isolated virtual server rented from a hosting provider, with its own operating system and allocated computing resources.

Packaged Linux operating-system release

A maintained bundle of the Linux kernel, system tools, package manager and applications distributed as one operating system.

Command interpreter / Bourne-Again Shell

A shell reads and runs commands; Bash is a widely used shell for interactive work and automation scripts.

Linux system and service manager

A system manager used by many Linux distributions to start the machine, supervise services and coordinate system resources.

Long-running background program

A program that runs in the background to provide an ongoing system or network function without direct interaction.

Running program / Process Identifier

A process is a running instance of a program; its PID is the number the operating system uses to identify it.

Advanced Package Tool / package source

APT installs and updates Debian-family software from configured repositories containing packages and their metadata.

Read, write and execute access rules

Operating-system rules that determine which users and groups may read, change or execute a file or directory.

Change mode / change owner

Unix-like commands for changing a file's permission bits with chmod or its owning user and group with chown.

Named value supplied to a process

A name-value setting inherited by programs and commonly used to provide paths, modes, credentials or other configuration.

Recorded events / managed log rollover

A log file records events; rotation archives or removes older logs so they do not grow without limit.

Secure Copy / SSH File Transfer Protocol

SSH-based tools for transferring files securely, with SFTP providing an interactive file-management protocol.

Incremental file-transfer utility

A tool that efficiently synchronises files by transferring only the differences needed between source and destination.

Top of a Unix-like filesystem

The highest directory in a Unix-like filesystem hierarchy, written as a forward slash, beneath which every other path sits.

Name for the local machine

A special name that resolves to the current machine's loopback address, allowing software to communicate with services running locally.

Software that handles web requests

Software that receives HTTP requests and returns static files or responses produced by an application.

Open-source web server

A widely used open-source web server that delivers static and dynamic sites through a configurable module-based architecture.

PHP FastCGI Process Manager

A PHP service that maintains pools of worker processes and handles FastCGI requests from a web server.

Linux, Apache or NGINX, MySQL or MariaDB, PHP

Common combinations of Linux, web-server, database and PHP software used together to run dynamic websites.

Per-site web-server configuration

A configuration section that lets one web server select different sites or settings according to the requested name or address.

Directory containing published site files

The filesystem directory a web server treats as the starting location for files exposed by a site.

Fast Common Gateway Interface

A protocol connecting a web server to long-running application processes without starting a new process for every request.

Three-digit result of an HTTP request

A three-digit response code showing whether an HTTP request succeeded, was redirected, failed at the client or failed at the server.

Move a client / internally remap a request

A redirect tells the client to use another URL, while a rewrite changes request handling inside the server.

Certificate authority / certificate automation client

Let's Encrypt issues free TLS certificates; Certbot obtains, installs and renews them automatically for supported servers.