Reference
Glossary
Browse our glossary of 30+ technical terms
Cryptography & Security
7What Is SHA-256? Hash Functions ExplainedUnderstand SHA-256: how this cryptographic hash function works, why it is secure, and where it is used — from blockchain to file verification.What Is MD5? Why It Is No Longer SecureLearn what MD5 is, how it works, and why it is considered cryptographically broken. Find out what to use instead for security-sensitive applications.What Is a JWT? (JSON Web Token) ExplainedLearn what JWT tokens are, how the three-part structure works, common signing algorithms, and security best practices for authentication.What Is AES Encryption? (Advanced Encryption Standard)Understand AES encryption: how it works, the difference between AES-128/192/256, block cipher modes, and where AES is used in everyday security.What Is RSA? Public-Key Cryptography ExplainedLearn how RSA public-key cryptography works, the math behind it, key size recommendations, and where RSA is used in HTTPS, SSH, and digital signatures.What Is HMAC? (Hash-Based Message Authentication Code)Learn what HMAC is, how it differs from a plain hash, why the key matters, and where HMAC-SHA256 is used in API authentication and webhooks.What Is Blood Alcohol Content (BAC)?Understand Blood Alcohol Content (BAC): how it is measured, what different BAC levels feel like, legal limits by country, and the Widmark formula.
Encoding & Formats
8What Is Base64? Encoding ExplainedLearn what Base64 encoding is, how it works, when to use it, and why it is not encryption. Includes examples and common use cases.What Is URL Encoding? (Percent-Encoding Explained)Learn what URL encoding (percent-encoding) is, which characters need encoding, the difference between encodeURI and encodeURIComponent, and practical examples.What Is Hexadecimal? Base-16 Number System ExplainedUnderstand the hexadecimal (base-16) number system: how to read HEX digits, convert between decimal, binary, and hex, and where hex is used in programming.What Is ASCII? Character Encoding ExplainedLearn what ASCII is, how the 128-character standard works, the difference between ASCII and Unicode/UTF-8, and practical uses in computing.What Is JSON? (JavaScript Object Notation) ExplainedLearn what JSON is, its syntax rules, supported data types, and why it became the universal data interchange format for APIs and configuration files.What Is CSV? (Comma-Separated Values) ExplainedUnderstand CSV format: syntax rules, handling special characters, comparison with JSON and Excel, and best practices for CSV data exchange.What Is Binary? Base-2 Number System ExplainedLearn the binary number system: how base-2 works, how to convert between binary and decimal, what bits and bytes are, and why computers use binary.What Is SQL? Structured Query Language ExplainedUnderstand SQL: the standard language for relational databases, core commands (SELECT, INSERT, UPDATE, DELETE), and how to use SQL to query and manipulate data.
Web & Dev
7What Is Regex? (Regular Expressions) ExplainedLearn what regular expressions (regex) are, essential syntax patterns, common use cases, and how to use regex for text matching and validation.What Is a Cron Job? Cron Syntax ExplainedUnderstand cron jobs and cron syntax: the five-field schedule format, common patterns, special keywords, and how to schedule recurring tasks.What Is a Unix Timestamp?Understand Unix timestamps: how seconds since the epoch work, timezone handling, the Year 2038 problem, and converting timestamps to human-readable dates.What Is Markdown? Lightweight Markup ExplainedLearn Markdown syntax, how it converts to HTML, extended Markdown flavors (GFM, CommonMark), and where Markdown is used today.What Is a MAC Address?Understand MAC addresses: what they are, OUI structure, the difference between MAC and IP addresses, and why MAC addresses can be spoofed.What Is IPv6? Internet Protocol Version 6 ExplainedLearn what IPv6 is, how its 128-bit address space solves IPv4 exhaustion, address notation, key features, and the current state of IPv6 adoption.What Is a Subnet Mask? IP Subnetting ExplainedUnderstand subnet masks, CIDR notation, how to calculate network address, broadcast address, and usable host range from any IP and subnet mask.
Colors & Design
2What Is a CSS Gradient?Learn about CSS gradients: linear-gradient, radial-gradient, and conic-gradient syntax, color stops, and techniques for professional gradient design.What Is the RGB Color Model?Learn the RGB color model: how Red, Green, Blue mixing works, the difference from CMYK, converting HEX to RGB, and practical use in CSS and design.
Text & Misc
6What Is a UUID? (Universally Unique Identifier)Understand UUIDs: what they are, how UUID v4 randomness works, the difference between versions, and when to use UUIDs in your applications.What Is Morse Code? History and How It WorksLearn what Morse code is, how dots and dashes encode letters and numbers, its history, and where it is still used today.What Is Lorem Ipsum? The Standard Filler TextLearn the origin of Lorem Ipsum placeholder text, what it actually says, why designers use it, and alternatives for modern mockups.What Is ROT13? Caesar Cipher ExplainedLearn what ROT13 is, how it works as a simple substitution cipher, why it is its own inverse, and its historical use on the internet.What Is a Passphrase? Passphrase vs PasswordLearn what a passphrase is, how it differs from a password, why passphrases can be both more secure and more memorable, and the diceware method.What Makes a Strong Password?Learn what makes a password strong: entropy, length, character sets, common patterns to avoid, and how password managers change everything.
Other
25What Is Encryption? How Data Is ProtectedEncryption converts readable data into ciphertext that only authorised parties can decode. Learn symmetric vs asymmetric, TLS, and why encryption matters.What Is OAuth? Authorisation ExplainedOAuth 2.0 lets users grant third-party apps limited access to their account without sharing passwords. Learn flows, tokens, and common pitfalls.What Is SSL/TLS? Secure Web Connections ExplainedSSL and TLS are cryptographic protocols that encrypt data between browsers and servers. Learn the difference, how HTTPS works, and what certificates do.What Is an API? How Applications Talk to Each OtherAn API (Application Programming Interface) defines how software components communicate. Learn REST, GraphQL, webhooks, and how APIs power modern apps.What Is Git? Version Control ExplainedGit is a distributed version control system. Learn commits, branches, merging, rebasing, and why Git is the foundation of modern software development.What Is Docker? Containers ExplainedDocker packages applications and their dependencies into portable containers. Learn images, containers, Dockerfiles, and how Docker differs from virtual machines.What Is a CDN? Content Delivery Networks ExplainedA CDN caches content at geographically distributed edge servers to reduce latency. Learn how CDNs work, when to use them, and how they improve web performance.What Is DNS? Domain Name System ExplainedDNS translates domain names like example.com into IP addresses. Learn how DNS resolution works, record types (A, CNAME, MX), TTL, and DNS security.What Is WebSocket? Real-Time Communication ExplainedWebSocket provides a persistent, full-duplex channel over a single TCP connection. Learn how it differs from HTTP, when to use it, and how it powers real-time apps.What Is Caching? Web Performance Deep DiveCaching stores copies of data to serve future requests faster. Learn browser cache, CDN cache, server-side cache (Redis, Memcached), Cache-Control headers, and invalidation.What Are Cookies? Browser Storage ExplainedCookies are small pieces of data stored in your browser by websites. Learn session vs persistent cookies, HttpOnly, Secure, SameSite, and how cookies power authentication.HTTP Status Codes ExplainedHTTP status codes tell clients the result of their request. Learn the 2xx success, 3xx redirect, 4xx client error, and 5xx server error classes with common examples.What Is UTF-8? Unicode Encoding ExplainedUTF-8 is the dominant character encoding for the web. Learn how Unicode code points map to bytes, why UTF-8 is backward-compatible with ASCII, and when to use UTF-16.What Is a Hash Function? Cryptographic Hashing ExplainedA hash function maps any input to a fixed-length digest. Learn SHA-256, MD5, collision resistance, one-way properties, and uses in passwords, integrity checks, and blockchains.What Is Rate Limiting? API Throttling ExplainedRate limiting restricts how often a client can call an API or resource. Learn token bucket, sliding window, leaky bucket algorithms, 429 Too Many Requests, and best practices.What Is SQL Injection? Web Security ExplainedSQL injection lets attackers manipulate database queries by inserting malicious SQL. Learn how it works, classic examples, and how to prevent it with parameterised queries.What Is XSS (Cross-Site Scripting)? Web Security ExplainedXSS lets attackers inject malicious scripts into web pages viewed by other users. Learn reflected, stored, DOM-based XSS, and how to prevent it with CSP and output encoding.What Is CSRF? Cross-Site Request Forgery ExplainedCSRF tricks authenticated users into unknowingly submitting malicious requests. Learn how CSRF tokens, SameSite cookies, and CORS headers prevent these attacks.What Is Web Scraping? Data Extraction ExplainedWeb scraping extracts data from websites programmatically. Learn how scrapers work, polite scraping practices, robots.txt, legal considerations, and common tools.What Is Minification? Code Compression for the WebMinification removes whitespace, comments, and redundant characters from HTML, CSS, and JavaScript to reduce file size and improve page load speed.What Is a REST API? RESTful Design PrinciplesREST is an architectural style for stateless HTTP APIs using URLs as resources and HTTP methods as actions. Learn constraints, best practices, and common mistakes.What Is a Regular Expression? Regex ExplainedRegular expressions (regex) are patterns used to match, search, and replace text. Learn syntax, character classes, quantifiers, groups, lookaheads, and common examples.What Is YAML? Configuration File Format ExplainedYAML is a human-friendly data serialisation format used for configuration files. Learn syntax, indentation rules, and how it compares to JSON and TOML.What Is Public-Key Cryptography? Asymmetric Encryption ExplainedPublic-key cryptography uses key pairs: public for encryption, private for decryption. Learn RSA, ECC, digital signatures, key exchange, and how PKI works.What Is Time Complexity? Big O Notation ExplainedTime complexity describes how algorithm runtime scales with input size. Learn Big O — O(1), O(log n), O(n), O(n log n), O(n²) — with real examples.