Web technologies contain long lists of jargon and abbreviations that are used in documentation and coding. This glossary provides definitions of words and abbreviations you need to know to successfully understand and build for the web.
Glossary of Terms
A
- Abstraction
- Accessibility
- Accessibility tree (AOM)
- Adobe Flash
- Ajax
- Algorithm
- Alignment container
- Alignment subject
- Alpha (alpha channel)
- ALPN
- API
- Apple Safari
- Application Context
- Argument
- ARIA
- ARPA
- Arpanet
- Array
- ASCII
- Asynchronous
- ATAG
- Attribute
B
- Bandwidth
- Base64
- Baseline
- beacon
- Bézier curve
- BiDi
- BigInt
- Blink
- Block
- Block (CSS)
- Block (scripting)
- Block cipher mode of operation
- Boolean
- Boot2Gecko
- Bootstrap
- Bounding Box
- Breadcrumb
- Brotli
- Browser
- Browsing context
- buffer
C
- Cache
- Cacheable
- CalDAV
- Call stack
- Callback function
- Canonical order
- Canvas
- Card sorting
- CardDAV
- caret
- CDN
- Certificate authority
- Certified
- Challenge-response authentication
- Character
- Character encoding
- Character set
- Chrome
- CIA
- Cipher
- Cipher suite
- Ciphertext
- Class
- Client hints
- Closure
- CMS
- Code splitting
- Codec
- Compile
- Compile time
- Computer Programming
- Conditional
- Constant
- Constructor
- Continuous Media
- Control flow
- Cookie
- Copyleft
- CORS
- CORS-safelisted request header
- CORS-safelisted response header
- Crawler
- CRLF
- Cross Axis
- Cross-site scripting
- CRUD
- Cryptanalysis
- Cryptographic hash function
- Cryptography
- CSP
- CSRF
- CSS
- CSS Object Model (CSSOM)
- CSS pixel
- CSS preprocessor
D
- Data structure
- Decryption
- Delta
- Denial of Service
- Descriptor (CSS)
- Deserialization
- Developer Tools
- DHTML
- Digest
- Digital certificate
- Distributed Denial of Service
- DMZ
- DNS
- Doctype
- Document directive
- document environment
- DOM (Document Object Model)
- Domain
- Domain name
- Domain sharding
- Dominator
- DoS attack
- DTLS (Datagram Transport Layer Security)
- DTMF (Dual-Tone Multi-Frequency signaling)
- Dynamic programming language
- Dynamic typing
E
- ECMA
- ECMAScript
- Effective connection type
- Element
- Empty element
- Encapsulation
- Encryption
- Endianness
- Engine
- Entity
- Entity header
- Event
- Exception
- Expando
F
- Fallback alignment
- Falsy
- Favicon
- Fetch directive
- Fetch metadata request header
- Firefox OS
- firewall
- First contentful paint
- First CPU idle
- First input delay
- First interactive
- First Meaningful Paint
- First paint
- First-class Function
- Flex
- Flex Container
- Flex Item
- Flexbox
- Forbidden header name
- Forbidden response header name
- Fork
- Fragmentainer
- frame rate (FPS)
- FTP
- FTU
- Function
- Fuzz testing
G
- Gaia
- Garbage collection
- Gecko
- General header
- GIF
- GIJ
- Git
- Global object
- Global scope
- Global variable
- Glyph
- Gonk
- Google Chrome
- GPL
- GPU
- Graceful degradation
- Grid
- Grid Areas
- Grid Axis
- Grid Cell
- Grid Column
- Grid container
- Grid Lines
- Grid Row
- Grid Tracks
- Guard
- Gutters
- Gzip compression
H
- Hash
- Head
- High-level programming language
- HMAC
- Hoisting
- Host
- Hotlink
- Houdini
- HPKP
- HSTS
- HTML
- HTML5
- HTTP
- HTTP header
- HTTP/2
- HTTP/3
- HTTPS
- Hyperlink
- Hypertext
I
- I18N
- IANA
- ICANN
- ICE
- IDE
- Idempotent
- Identifier
- IDL
- IETF
- IIFE
- IMAP
- Immutable
- Index
- IndexedDB
- Information architecture
- Inheritance
- Input method editor
- Instance
- Internationalization
- Internet
- Intrinsic Size
- IP Address
- IPv4
- IPv6
- IRC
- ISO
- ISP
- ITU
J
K
L
- Latency
- Layout viewport
- Lazy load
- LGPL
- Ligature
- Local scope
- Local variable
- Locale
- Localization
- Long task
- Loop
- Lossless compression
- lossy compression
- LTR (Left To Right)
M
- Main Axis
- Main thread
- markup
- MathML
- Media
- Media (Audio-visual presentation)
- Media (CSS)
- Metadata
- Method
- Microsoft Edge
- Microsoft Internet Explorer
- Middleware
- mime
- MIME type
- minification
- MitM
- Mixin
- Mobile First
- Modem
- Modern web apps
- Modularity
- Mozilla Firefox
- Mutable
- MVC
N
- Namespace
- NaN
- NAT
- Native
- Navigation directive
- Netscape Navigator
- Network throttling
- NNTP
- Node
- Node (DOM)
- Node (networking)
- Node.js
- non-normative
- Normative
- Null
- Nullish value
- Number
O
P
- P2P
- PAC
- Packet
- Page load time
- Page prediction
- Parameter
- Parent object
- Parse
- Parser
- Perceived performance
- Percent-encoding
- PHP
- Pixel
- Placeholder names
- Plaintext
- PNG
- Polyfill
- Polymorphism
- POP3
- Port
- Prefetch
- Preflight request
- Prerender
- Presto
- Primitive
- Privileged
- privileged code
- Progressive Enhancement
- Progressive web apps
- Promise
- Property
- Property (CSS)
- Property (JavaScript)
- Protocol
- Prototype
- Prototype-based programming
- Proxy server
- Pseudo-class
- Pseudo-element
- Pseudocode
- Public-key cryptography
- Python
Q
R
- RAIL
- Random Number Generator
- Raster image
- RDF
- Real User Monitoring (RUM)
- Recursion
- Reference
- Reflow
- Regular expression
- Rendering engine
- Repo
- Reporting directive
- Request header
- Resource Timing
- Response header
- Responsive web design
- REST
- RGB
- RIL
- Robots.txt
- Round Trip Time (RTT)
- Routers
- RSS
- RTCP (RTP Control Protocol)
- RTF
- RTL (Right to Left)
- RTP (Real-time Transport Protocol) and SRTP (Secure RTP)
- RTSP: Real-time streaming protocol
- Ruby
S
- Safe
- Same-origin policy
- SCM
- Scope
- Screen reader
- Script-supporting element
- Scroll container
- Scrollport
- SCTP
- SDP
- Search engine
- Second-level Domain
- Secure Sockets Layer (SSL)
- Selector (CSS)
- Self-Executing Anonymous Function
- Semantics
- SEO
- Serialization
- Server
- Server Timing
- Session Hijacking
- SGML
- Shadow tree
- Shim
- Signature
- Signature (functions)
- Signature (security)
- SIMD
- Simple header
- Simple response header
- SISD
- Site
- Site map
- SLD
- Sloppy mode
- Slug
- Smoke Test
- SMPTE (Society of Motion Picture and Television Engineers)
- SMTP
- Snap positions
- SOAP
- SPA (Single-page application)
- Specification
- Speculative parsing
- Speed index
- SQL
- SQL Injection
- SRI
- Stacking context
- State machine
- Statement
- Static method
- Static typing
- Strict mode
- String
- STUN
- Style origin
- Stylesheet
- SVG
- SVN
- Symbol
- Symmetric-key cryptography
- Synchronous
- Syntax
- Syntax error
- Synthetic monitoring
T
- Tag
- TCP
- TCP handshake
- TCP slow start
- Telnet
- Texel
- Thread
- Three js
- Time to first byte
- Time to interactive
- TLD
- TOFU
- Transmission Control Protocol (TCP)
- Transport Layer Security (TLS)
- Tree shaking
- Trident
- Truthy
- TTL
- TURN
- Type
- Type coercion
- Type conversion
U
V
W
- W3C
- WAI
- WCAG
- Web performance
- Web server
- Web standards
- WebAssembly
- WebDAV
- WebExtensions
- WebGL
- WebIDL
- WebKit
- WebM
- WebP
- WebRTC
- WebSockets
- WebVTT
- WHATWG
- Whitespace
- World Wide Web
- Wrapper
X
Other
- ALPN
- at-rule
- Attack
- Byte-Order Mark
- Character set
- client
- cryptosystem
- debug
- digital signature
- execution
- flex-direction
- GLSL
- Interface
- Library
- Memory management
- routers
- Self-Executing Anonymous Function
- Stylesheet
- Vector image