IT Glossary & Dictionary

A virtual filesystem that exports information about kernel subsystems, hardware devices, and device drivers in a structured hierarchy.

The primary command for managing systemd services, including starting, stopping, enabling, and checking service status.

A system and service manager for Linux that initializes the system and manages services, logging, and more.

A systemd unit that triggers services on a schedule or at specific events, serving as a modern alternative to cron jobs.

A utility for creating and extracting archive files that combine multiple files and directories into a single file.

The fundamental communication protocol suite of the internet that defines how data is packaged, addressed, transmitted, and received.

Two transport layer protocols: TCP provides reliable, ordered delivery while UDP provides fast, connectionless delivery without guarantees.

The implied cost of additional rework caused by choosing a quick solution now instead of a better approach that would take longer.

An open-source tool for provisioning and managing cloud infrastructure using declarative configuration files.

The smallest unit of execution within a process, allowing concurrent operations to run within a single program.

A database optimized for storing and querying timestamped data points like metrics, sensor readings, and event logs.

A terminal multiplexer that allows running multiple terminal sessions within a single window, with detach/reattach capability.

A rate limiting algorithm that allows burst traffic by accumulating tokens at a fixed rate and consuming them per request.

Interactive process viewers that display real-time system resource usage including CPU, memory, and running processes.

A network diagnostic tool that shows the path packets take from source to destination, listing each hop along the way.

A sequence of database operations that are treated as a single unit — either all succeed or all are rolled back.

A database object that automatically executes a specified function when certain events (INSERT, UPDATE, DELETE) occur on a table.

A source control strategy where developers integrate small changes directly into the main branch frequently, often multiple times per day.

A methodology of twelve best practices for building modern, scalable, maintainable software-as-a-service applications.

A security method requiring two different forms of identification before granting access to an account.

Optional annotations that indicate the expected types of variables, function parameters, and return values.

A typed superset of JavaScript that adds static type checking, interfaces, and advanced IDE support to JavaScript development.

A command that sets or displays resource limits for user processes, such as maximum open files or memory usage.

Testing individual components or functions of a program in isolation to verify they work correctly.

A database operation that inserts a new row if it does not exist, or updates the existing row if it does.

A lightning-fast ASGI server for Python, commonly used to serve FastAPI and other async web applications.

A PostgreSQL maintenance operation that reclaims storage from dead tuples and updates statistics for the query planner.

A tool by HashiCorp for securely managing secrets, encryption keys, and certificates with dynamic secret generation.

A system that records changes to files over time, allowing you to recall specific versions, collaborate, and track history.

A virtual table defined by a SQL query that provides a simplified or restricted view of data from one or more tables.

An isolated Python environment that maintains its own set of packages, independent of the system Python installation.

A software-based emulation of a physical computer that runs its own operating system and applications.

A logical grouping of network devices that creates separate broadcast domains on the same physical network infrastructure.

An isolated virtual network within a cloud provider where you can launch resources with full control over IP addressing, routing, and security.

A technology that creates an encrypted tunnel between your device and a remote server, securing internet traffic.

Automated testing that identifies known security weaknesses in systems, applications, and network infrastructure.

A security solution that filters and monitors HTTP traffic between a web application and the internet, blocking common attacks.

The := operator that assigns a value to a variable as part of an expression, introduced in Python 3.8.

The practice of designing websites that can be used by people with disabilities, following WCAG guidelines.

A binary instruction format that enables near-native performance execution of code in web browsers alongside JavaScript.

Techniques for storing copies of web resources at various levels to reduce server load, bandwidth, and response times.

A set of browser-native APIs for creating reusable, encapsulated custom HTML elements with their own styling and behavior.

Techniques for loading custom fonts efficiently to minimize their impact on page load performance and visual stability.

A mechanism where a server sends real-time HTTP POST notifications to a specified URL when specific events occur.

A security mechanism that verifies webhook payloads are authentic and unmodified using cryptographic signatures.

Techniques to make websites load faster and respond more quickly, improving user experience and search engine rankings.

A communication protocol that enables full-duplex, real-time data exchange between a browser and server over a single connection.

Google's metrics for measuring user experience quality, including loading speed, interactivity, and visual stability of web pages.