Glossary
Quick, plain-English definitions of the technical terms used across our tools and guides. Each entry includes related tools and guides for deeper exploration.
- Base32
- An encoding that represents binary data using 32 alphabet characters (A–Z and 2–7). Case-insensitive and free of special characters, making it suitable for TOTP secrets, DNS records, and human-typed codes. Less dense than Base64 but easier to enter without errors.
- Base58
- A binary-to-text encoding that uses 58 alphanumeric characters, excluding visually ambiguous ones (0, O, I, l). Used by Bitcoin addresses, IPFS, and identifiers where humans might transcribe the value by sight or voice. Slightly larger output than Base64 but much friendlier for human use.
- Base64
- An encoding that represents binary data using 64 alphabet characters (A–Z, a–z, 0–9, +, /). The de-facto standard for embedding binary data in text-only contexts like JSON, JWTs, email attachments, and data URLs. Output is about 33% larger than the input.
- bcrypt
- A password hashing function from 1999 based on the Blowfish cipher. Designed to be deliberately slow with a tunable cost factor. Widely supported across languages and still safe in 2026 when configured with cost 12 or higher.
- BMI
- Body Mass Index: a number derived from a person's weight and height (weight in kg divided by height in meters squared). Used as a rough screening indicator of weight categories. Has known limitations and should not replace medical assessment.
- Box Shadow
- A CSS property that adds a shadow effect around an element's frame. Configurable via horizontal/vertical offset, blur radius, spread distance, and color, with optional inset for inner shadows.
- Cargo Cult Programming
- Writing code by imitating patterns without understanding why they work. Common in security (storing passwords with SHA-256 plus a salt is a textbook example) and in 'works for me' fixes that get propagated without verification.
- CSS Gradient
- A CSS feature that creates a smooth transition between two or more colors. Linear gradients flow along a straight line; radial gradients emanate from a point. Useful for backgrounds, buttons, and visual emphasis without using image files.
- Data URL
- A URL scheme ('data:') that embeds a file's contents directly inside the URL itself, typically with Base64 encoding. Common for small images inlined into CSS or HTML. Loses efficiency for files larger than ~4 KB due to Base64 overhead.
- GraphQL
- A query language for APIs that lets clients request exactly the data they need from a single endpoint. Eliminates over-fetching and under-fetching compared to REST, at the cost of harder caching and a more complex server implementation.
- gRPC
- A high-performance RPC framework built on HTTP/2 and Protocol Buffers. Provides binary efficiency, streaming, and cross-language code generation, but is not directly callable from browsers without a gRPC-Web proxy.
- Hash Function
- A function that maps input of any size to a fixed-size output. Cryptographic hashes (SHA-256, SHA-1) are one-way and collision-resistant; password hashes (Argon2, bcrypt) are deliberately slow. Not the same as encryption — hashes cannot be reversed.
- HEIC
- High Efficiency Image Container, the default photo format on modern iPhones. Produces files about half the size of JPG at comparable quality. Limited browser support — typically must be converted to JPG, WebP, or AVIF for web use.
- HEX Color
- A 6-digit hexadecimal representation of an RGB color, prefixed with '#'. Each pair of digits (00–FF) specifies red, green, and blue channels. '#FF0000' is pure red; '#000000' is black; '#FFFFFF' is white.
- HSL
- A color model representing hue, saturation, and lightness. More intuitive than RGB for human adjustments — for example, increasing lightness uniformly brightens a color without needing to recalculate all three RGB channels.
- JSON
- JavaScript Object Notation: a text-based data format using key-value pairs and arrays. The default for APIs and configuration files because of its strict grammar and universal language support. Does not allow comments or trailing commas.
- JWT
- JSON Web Token: a compact, URL-safe token containing a header, payload, and signature, separated by dots. Used for authentication and authorization. The payload is Base64-encoded JSON — readable, but tamper-evident because of the signature.
- Lorem Ipsum
- Placeholder Latin-looking text used in design mockups and layout drafts. The standard text begins with 'Lorem ipsum dolor sit amet...' and has no real meaning, allowing designers to evaluate layout without distraction from content.
- MD5
- A 128-bit hash function from 1992. Completely broken for security purposes — collisions can be created in seconds on consumer hardware. Acceptable only for non-adversarial integrity checks (such as detecting accidental file corruption).
- Mojibake
- Character encoding garbage, typically produced when text encoded in one character set (UTF-8) is interpreted using another (Windows-1252, Shift-JIS). The result is unreadable symbols like '’' or '譁字蛹'. Caused by missing or wrong charset metadata.
- Percent Encoding
- The mechanism that escapes characters in URLs by replacing them with '%' followed by their hex code. ' ' becomes '%20', '?' becomes '%3F', and so on. Required for safely embedding special characters in URL paths and query parameters.
- Punycode
- An encoding used to represent Unicode characters in ASCII-only domain names. A domain containing 'café' is stored as 'xn--caf-dma'. Phishing attacks sometimes use punycode to register lookalike domains using Cyrillic or Greek characters.
- QR Code
- A 2D barcode that encodes text, URLs, or other data in a square pattern of black and white modules. Readable by smartphone cameras. Originally invented in 1994 for tracking automotive parts; now ubiquitous for sharing URLs and payments.
- RAID
- Redundant Array of Independent Disks: a method of combining multiple physical disks into one logical volume for performance, fault tolerance, or both. RAID is not a backup — it protects against drive failure but not against deletion, corruption, or site disasters.
- Regex
- Regular expression: a pattern that describes a set of strings. Used for searching, validation, splitting, and substitution. Most languages share core syntax (literals, character classes, quantifiers, anchors) but differ on advanced features like lookbehinds.
- REST
- Representational State Transfer: an architectural style for APIs that uses HTTP methods (GET, POST, PUT, DELETE) and resource-shaped URLs. The default style for public APIs because of its simplicity, browser compatibility, and CDN cacheability.
- RGB
- Red-Green-Blue color model used by displays. Each channel ranges 0–255 in standard 8-bit color (or 0–1.0 in float form). 'rgb(255, 0, 0)' is pure red. Easily convertible to/from HEX and HSL representations.
- SHA-256
- A cryptographic hash function producing a 256-bit (32-byte) digest. Part of the SHA-2 family standardized by NIST. As of 2026, the default choice for new applications needing a fast cryptographic hash — used in TLS certificates, Git, and Bitcoin.
- Slug
- A URL-friendly version of a string, typically lowercase with hyphens between words ('how-to-write-a-blog-post'). Used in routing for blog posts, products, and tools. Should be stable — never change a slug after publishing or you break inbound links.
- TOML
- Tom's Obvious Minimal Language: a configuration file format with INI-like sections, comments, and an unambiguous type system. Used by Rust's Cargo, Python's pyproject.toml, and many modern tool configs. Less suited to deeply nested data than YAML or JSON.
- TOTP
- Time-based One-Time Password: a 6-digit code generated from a shared secret and the current time. The standard second-factor authentication method, supported by authenticator apps like Authy and Google Authenticator. The shared secret is typically Base32-encoded.
- ULID
- Universally Unique Lexicographically Sortable Identifier: a 128-bit ID encoded as 26 Crockford Base32 characters. The first 48 bits encode a millisecond timestamp, so ULIDs sort chronologically. URL-friendly alternative to UUID v7.
- Unix Timestamp
- An integer representing the number of seconds since 1970-01-01 00:00:00 UTC. The default time format in Unix-like systems and many APIs. Often confused with milliseconds-since-epoch — always confirm which unit a system expects.
- URL Encoding
- Synonym for percent encoding. The process of replacing characters that have special meaning in URLs (spaces, '?', '&', '#', etc.) with '%' followed by their hex code, so the URL can be transmitted safely.
- UUID
- Universally Unique Identifier: a 128-bit value typically displayed as 32 hex characters with dashes ('550e8400-e29b-41d4-a716-446655440000'). UUID v4 is fully random; v7 encodes a timestamp at the start for sortability. Used widely as database primary keys.
- WebP
- A modern image format developed by Google that supports both lossy and lossless compression plus transparency and animation. Typically 25–35% smaller than JPG at equivalent quality. Universally supported in modern browsers.
- YAML
- A human-friendly data serialization format that uses indentation instead of brackets. Popular for configuration in Kubernetes, GitHub Actions, and CI tools. Beware of implicit type coercion — 'NO' becomes false, '01' becomes octal — which has caused production incidents.
Related guides: Base64 vs Base58 vs Base32
Related guides: Base64 vs Base58 vs Base32
Related tools: Base64 Encoder / Decoder
Related tools: BMI-Rechner
Related tools: CSS-Box-Shadow-Generator
Related guides: Hash Functions Explained
Related tools: CSS-Gradient-Generator
Related tools: Base64 Encoder / Decoder
Related guides: Base64 Encoding Explained
Related guides: REST vs GraphQL vs gRPC
Related guides: REST vs GraphQL vs gRPC
Related tools: Hash-Generator (SHA-256 / SHA-1 / MD5)
Related guides: Hash Functions Explained
Related tools: Bildformat-Konverter
Related guides: Image Format Comparison
Related tools: Farbcode-Konverter
Related tools: Farbcode-Konverter
Related tools: JSON Formatter & Validator
Related tools: JWT-Decoder
Related tools: Lorem-Ipsum-Generator
Related guides: Hash Functions Explained
Related guides: JSON Best Practices
Related tools: URL Encoder / Decoder
Related tools: URL-Sicherheitscheck
Related guides: URL Safety Check Guide
Related tools: QR-Code-Generator
Related tools: RAID-Rechner
Related guides: RAID Level Comparison Guide
Related tools: Regex-Tester
Related guides: Regex Basics
Related guides: REST vs GraphQL vs gRPC
Related tools: Farbcode-Konverter
Related tools: Hash-Generator (SHA-256 / SHA-1 / MD5)
Related guides: Hash Functions Explained
Related tools: Text zu URL-Slug
Related guides: JSON vs YAML vs TOML
Related guides: Base64 vs Base58 vs Base32
Related tools: UUID-Generator
Related guides: UUID v4 vs UUID v7 vs ULID
Related tools: Unix-Timestamp-Konverter
Related tools: URL Encoder / Decoder
Related tools: UUID-Generator
Related guides: UUID v4 vs UUID v7 vs ULID
Related guides: Image Format Comparison
Related guides: JSON vs YAML vs TOML
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