Reference

Glossary

Plain-English definitions of the AI, data, health, security, and web terms used across Open Web Lab — each linked to the relevant free tool or guide.

AI & NLP

Sentiment Analysis: An NLP technique that classifies text as positive, negative, or neutral based on its emotional tone. Try the sentiment analysis tool.
NLP (Natural Language Processing): A field of AI focused on enabling computers to understand, interpret, and generate human language — powering search, chatbots, translation, and sentiment analysis.
Tokenization: The process of splitting text into smaller units (tokens) — words or subwords — so a model can process it numerically.
Transformer: A neural network architecture that uses an attention mechanism to weigh relationships between all words in a sequence. It is the basis of modern large language models.
LLM (Large Language Model): A large neural network trained on vast amounts of text to predict the next token and generate human-like language. Try the AI text generator.

JSON: JavaScript Object Notation — a lightweight text format for structured data built from objects and arrays. Format it with the JSON formatter.
CSV: Comma-Separated Values — a plain-text format for tabular data, one record per line. Visualize one with the CSV to Chart tool.
API: Application Programming Interface — a defined contract that lets software systems request and exchange data, usually as JSON over HTTP.
Static Site Generation (SSG): Pre-rendering pages to static HTML at build time, so the server delivers ready files instantly — fast, secure, and SEO-friendly. This site is built with SSG.

BMI (Body Mass Index): A screening number relating weight to height (kg ÷ m²). Calculate yours with the BMI calculator.
HRV (Heart Rate Variability): The variation in time between consecutive heartbeats. Higher HRV generally signals better recovery and stress resilience. Read the HRV guide.
Sleep Cycle: A roughly 90-minute progression through light, deep, and REM sleep that repeats nightly. Time yours with the sleep calculator.
REM Sleep: Rapid Eye Movement sleep — the dreaming stage linked to memory consolidation and learning, occurring more toward morning.
Heart Rate Zone: One of five heart-rate intensity ranges used to target specific training effects. Find yours with the heart rate zone calculator.
Karvonen Formula: A method to calculate target heart rate that factors in your resting rate (heart rate reserve), giving more personalised zones than the simple percentage-of-max method.

Entropy (passwords): A measure (in bits) of how unpredictable a password is. More bits mean exponentially more guesses to crack. Test a password with the password checker.
Brute-Force Attack: An attack that systematically tries every possible combination until it finds the correct password or key. Longer, higher-entropy passwords defeat it.
Passphrase: A password built from several unrelated words — long and memorable, yet very hard to crack thanks to its length.
Base64: An encoding — not encryption — that represents binary data with 64 printable ASCII characters. Use the Base64 tool.
Two-Factor Authentication (2FA): A security method requiring two independent forms of verification — typically a password plus a one-time code — so a stolen password alone is not enough.

WCAG: Web Content Accessibility Guidelines — the international standard for accessible web content, including color contrast rules. Check colors with the contrast checker.
Contrast Ratio: The luminance difference between text and its background, from 1:1 to 21:1. WCAG AA requires at least 4.5:1 for normal text.
Readability: How easy text is to read, scored by formulas like Flesch Reading Ease. Test yours with the readability analyzer.
Meta Description: An HTML tag (~155 characters) summarising a page in search results. It influences click-through rate. Preview it with the meta tags previewer.
Open Graph: A set of og: meta tags controlling how a link looks when shared on social media — title, description, and a 1200×630 image (PNG/JPG, not SVG).
Canonical URL: A <link rel="canonical"> tag that tells search engines the preferred version of a page, preventing duplicate-content issues.
Markdown: A lightweight markup syntax for formatting plain text with simple symbols. Try the Markdown editor.

Put these terms to work with free, in-browser tools.