An AI system capable of autonomously perceiving its environment, planning actions, using tools, and completing multi-step tasks — not just answering questions, but executing work with real-world effects.

The company behind Claude, founded in 2021 by former OpenAI researchers. Its core mission is developing safe and beneficial AI. Anthropic's safety research directly shapes Claude's design philosophy and behavioral characteristics.

An interface that lets developers call Claude's capabilities programmatically, integrating them into their own applications, services, or automated workflows. The API gives you full control over System Prompt, model version, Temperature, and other parameters to build specialized AI applications.

Interactive content Claude generates in a separate window alongside the conversation, including code, web pages, SVG graphics, and more. Lets you preview and interact with outputs directly inside Claude.ai without copying to external tools.

Claude's three capability tiers: Haiku is fastest and cheapest, Sonnet balances speed and capability, Opus is most powerful but slowest and most expensive.

An AI training method proposed by Anthropic that trains the model to self-evaluate and improve according to an explicit set of behavioral principles (the "constitution"), rather than relying entirely on human subjective scoring of individual responses. One of the core training mechanisms behind Claude's honesty and safety.

The maximum amount of text Claude can hold in memory during a single session — everything beyond it gets forgotten.

Further training a pre-trained language model on domain-specific data to make its behavior better suited to specific needs. The core technique for turning a generalist AI into a domain specialist.

When AI generates plausible-sounding but factually wrong or invented information — stated with full confidence but simply not true.

The last date at which an AI model's training data was updated. Events after this date are completely unknown to the model. Claude's knowledge cutoff is end of August 2025 — asking about post-cutoff events may yield outdated or incorrect information.

An AI model trained on massive text data with the ability to understand and generate human language. Claude, GPT-4, and Gemini are all LLMs. "Large" refers to the enormous number of model parameters, not the length of text output.

An AI's ability to simultaneously process and understand multiple input types, including text, images, and documents. Claude's multimodal capabilities let you upload screenshots, photos, and PDFs to ask questions directly — no need to convert everything to text first.

An architecture that lets AI retrieve relevant information from an external knowledge base before generating a response — solving knowledge cutoff and hallucination problems.

A parameter controlling how predictable or creative Claude's responses are — 0 is deterministic, 1 is maximally random.

The basic unit AI uses to process text — roughly 3/4 of an English word, or about 1-2 tokens per Chinese character.