Web4
A loose term for a more agentic web where AI agents can understand content, use tools, and help users complete tasks.
Related guidePlain-English reference
Glossary
Short definitions for the terms that appear across Web4, AI agents, agent-ready websites, and AI-readable content.
Web 4.0
Another name for Web4, usually used to describe the next stage of the web after social platforms and Web3 infrastructure.
Related guideAgentic Web
A web designed for both humans and AI agents, with clearer structure, actions, summaries, and machine-readable context.
Related guideAI Agent
Software that can interpret a goal, make a plan, use tools, and take steps with some level of autonomy.
Related guideAgentic AI
AI behavior that can reason through steps and act toward goals, even if it is not packaged as one specific agent app.
Related guideAgent-ready Website
A website that is easy for AI agents and AI search systems to read, summarize, navigate, and trust.
Related guidellms.txt
A proposed text file that gives AI systems a concise map of a website's important pages and documentation.
Related guiderobots.txt
A file that gives crawlers basic instructions about which parts of a site may be crawled.
Related guidesitemap.xml
An XML file that lists important URLs so search engines can discover and revisit pages more easily.
Related guideStructured Data
Machine-readable metadata, often JSON-LD, that describes pages, articles, FAQs, products, tools, and other entities.
Related guideSchema.org
A shared vocabulary for structured data used by search engines and other systems to understand web pages.
Related guideWeb3
A web movement focused on ownership, wallets, tokens, blockchain networks, and decentralized infrastructure.
Related guideBlockchain
A shared ledger maintained by a network, often used for assets, smart contracts, identity, and audit trails.
Related guideSmart Contract
Code deployed on a blockchain that can execute rules such as transfers, permissions, or escrow logic.
Related guideAI Search
Search experiences that answer, summarize, compare, or recommend using AI models rather than only listing links.
Related guideGenerative Engine Optimization
The practice of making content easier for AI answer engines to understand, cite, and summarize accurately.
Related guideMCP
Model Context Protocol, a way for AI systems to connect with tools, data sources, and local services.
Related guideA2A
Agent-to-agent communication, where separate AI agents coordinate or exchange task context.
Related guideAgentic Browser
A browser or browsing layer where an AI agent can interpret pages, click, fill forms, and help complete tasks.
Related guideTool Use
The ability of an AI model or agent to call external tools such as search, code execution, files, or website actions.
Related guide