Developer Tools Glossary

Encoding & Decoding

Base64 Encoding

A method of encoding binary data into ASCII text using 64 different characters (A-Z, a-z, 0-9, +, /). Commonly used for embedding images in HTML/CSS, email attachments, and data URLs. Increases data size by approximately 33%.

Example: "Hello" → "SGVsbG8="

Use Cases: Data URLs, email attachments, JWT tokens, storing binary data in JSON/XML

URL Encoding (Percent Encoding)

Converts special characters into percent signs followed by hexadecimal values to make them safe for URL transmission. Spaces become %20, @ becomes %40, etc.

Example: "hello world" → "hello%20world"

Use Cases: Query parameters, form submissions, API endpoints, social sharing links

UTF-8

Universal character encoding that supports all human languages. Variable-length encoding using 1-4 bytes per character. Backward compatible with ASCII and the standard for web development.

Use Cases: All web content, database storage, file encoding, internationalization

ASCII

American Standard Code for Information Interchange. 7-bit character encoding supporting 128 characters (0-127), including English letters, numbers, and basic symbols.

Cryptography & Security

Hash Function

One-way cryptographic function that converts input of any size into fixed-size output. Same input always produces same output, but output cannot be reversed to find input.

Common Algorithms: MD5 (128-bit), SHA-1 (160-bit), SHA-256 (256-bit), SHA-512 (512-bit)

Use Cases: Password storage, file integrity verification, digital signatures, cache busting

MD5 (Message Digest 5)

128-bit hash function. Fast but considered cryptographically broken—do NOT use for security. Still useful for checksums and non-security applications.

Output Length: 32 hexadecimal characters

SHA (Secure Hash Algorithm)

Family of cryptographic hash functions. SHA-256 and SHA-512 are current standards for security applications.

• SHA-1: 160-bit, deprecated for security use
• SHA-256: 256-bit, current standard for most applications
• SHA-512: 512-bit, maximum security

Encryption

Two-way process that transforms data into unreadable format using a key. Can be reversed with the correct key. Unlike encoding (which is format transformation) or hashing (which is one-way).

Types: Symmetric (same key for encryption/decryption), Asymmetric (public/private key pairs)

Two-Factor Authentication (2FA)

Security method requiring two different types of identification: something you know (password) + something you have (phone, security key) or something you are (biometric).

Methods: SMS codes, authenticator apps, hardware keys, biometrics

Data Formats

JSON (JavaScript Object Notation)

Lightweight data interchange format using human-readable text. Supports strings, numbers, booleans, null, arrays, and objects. Language-independent despite JavaScript in the name.

File Extension: .json

MIME Type: application/json

XML (eXtensible Markup Language)

Markup language for encoding documents in human-readable and machine-readable format. More verbose than JSON but supports attributes, namespaces, and schemas.

Use Cases: Configuration files, SOAP APIs, RSS feeds, SVG graphics

YAML (YAML Ain't Markup Language)

Human-readable data serialization format. Uses indentation instead of brackets. Popular for configuration files.

Use Cases: Docker Compose, Kubernetes configs, CI/CD pipelines, Ansible playbooks

CSV (Comma-Separated Values)

Simple format for tabular data where each line is a record and fields are separated by commas. Easy to import/export from spreadsheets and databases.

Web Development

API (Application Programming Interface)

Set of rules and protocols allowing different software applications to communicate. Web APIs typically use HTTP requests to retrieve or send data.

Types: REST, GraphQL, SOAP, gRPC

REST (Representational State Transfer)

Architectural style for web APIs using HTTP methods (GET, POST, PUT, DELETE) and stateless communication. Most common API design pattern.

HTTP (Hypertext Transfer Protocol)

Protocol for transmitting data over the web. Request-response model where clients send requests and servers send responses.

Common Methods: GET (retrieve), POST (create), PUT (update), DELETE (remove)

HTTPS (HTTP Secure)

Encrypted version of HTTP using SSL/TLS. Essential for security—encrypts all data transmitted between client and server.

MIME Type (Multipurpose Internet Mail Extensions)

Standard way to identify file types on the internet. Format: type/subtype

Examples: text/html, application/json, image/png, video/mp4

Text & Formatting

Lorem Ipsum

Placeholder text used in design and publishing. Derived from Latin text by Cicero. Provides realistic text distribution without meaningful content.

Origin: "Lorem ipsum dolor sit amet, consectetur adipiscing elit..."

camelCase

Naming convention where first word is lowercase and subsequent words are capitalized. No spaces or punctuation.

Example: myVariableName, getUserInfo, calculateTotalPrice

Used In: JavaScript, Java, TypeScript variables and functions

PascalCase

Similar to camelCase but first letter is also capitalized.

Example: MyClassName, UserProfile, ProductController

Used In: Class names, React components, C# conventions

snake_case

Words separated by underscores, all lowercase.

Example: my_variable_name, get_user_info, calculate_total

Used In: Python, Ruby, SQL, file naming

kebab-case

Words separated by hyphens, all lowercase.

Example: my-component-name, user-profile, product-details

Used In: CSS class names, HTML attributes, URLs

Identifiers & Tokens

UUID (Universally Unique Identifier)

128-bit number used to uniquely identify information. Virtually guaranteed to be unique without central coordination.

Format: 8-4-4-4-12 hexadecimal digits (e.g., 550e8400-e29b-41d4-a716-446655440000)

Versions: v1 (timestamp), v4 (random), v5 (namespace+name)

GUID (Globally Unique Identifier)

Microsoft's term for UUID. Functionally identical to UUID.

JWT (JSON Web Token)

Compact, URL-safe token format for transmitting claims between parties. Consists of three Base64URL-encoded parts: header, payload, signature.

Structure: xxxxx.yyyyy.zzzzz

Use Cases: Authentication, authorization, information exchange

QR Codes & Barcodes

QR Code (Quick Response Code)

Two-dimensional barcode that stores data in black and white squares. Can store up to 4,296 alphanumeric characters or 7,089 numeric characters.

Error Correction Levels: L (7%), M (15%), Q (25%), H (30%)

Use Cases: URLs, WiFi credentials, payment info, contact cards, authentication

Data URL

Scheme allowing inline embedding of data in documents. Uses base64 encoding to include binary data in text format.

Format: data:[MIME-type];base64,[encoded-data]

Example: data:image/png;base64,iVBORw0KGg...

Image & Color

Hex Color

Six-digit hexadecimal color representation. Format: #RRGGBB where RR=red, GG=green, BB=blue.

Example: #FF5733 (red-orange), #000000 (black), #FFFFFF (white)

RGB (Red Green Blue)

Color model using intensity values (0-255) for red, green, and blue channels.

Format: rgb(255, 87, 51)

With Alpha: rgba(255, 87, 51, 0.5) for transparency

HSL (Hue Saturation Lightness)

Color model using hue (0-360°), saturation (0-100%), and lightness (0-100%). More intuitive for color manipulation.

Format: hsl(204, 70%, 53%)

Image Compression

Reducing file size of images. Lossy compression (JPEG) discards some data; lossless compression (PNG, WebP) preserves all data.

Formats: JPEG (photos), PNG (graphics with transparency), WebP (modern, smaller sizes), SVG (vector graphics)

Security Concepts

XSS (Cross-Site Scripting)

Security vulnerability allowing attackers to inject malicious scripts into web pages. Prevent by sanitizing user input and escaping output.

CSRF (Cross-Site Request Forgery)

Attack forcing users to execute unwanted actions on authenticated websites. Prevent with CSRF tokens and SameSite cookies.

CORS (Cross-Origin Resource Sharing)

Security feature controlling which domains can access your API. Browsers block cross-origin requests unless explicitly allowed.

SSL/TLS

Cryptographic protocols providing secure communication over networks. TLS (Transport Layer Security) is the modern version of SSL (Secure Sockets Layer).

Development Tools

Minification

Removing unnecessary characters (whitespace, comments, newlines) from code without changing functionality. Reduces file size for faster loading.

Beautify/Pretty Print

Formatting code with proper indentation and spacing for human readability. Opposite of minification.

Validation

Checking data against rules or schemas to ensure correctness. Examples: JSON validation, form validation, data type checking.

Regex (Regular Expression)

Pattern-matching language for searching and manipulating text. Powerful but complex syntax for finding patterns in strings.

Example: /\d{3}-\d{3}-\d{4}/ matches phone numbers like 123-456-7890