Claude

Claude is Anthropic's family of large language models, accessible through a web and mobile chat app, a desktop app, a developer API, and Claude Code for working in a terminal or IDE. It handles conversation, writing, research, coding, and document analysis, and can operate as an agent that reads files, calls tools, and carries out multi-step tasks instead of just replying in a single turn. Anthropic offers it in tiers: Haiku for speed and low cost, Sonnet as the general-purpose default, and Opus for the hardest reasoning and coding work, with model choice depending on the balance of speed, cost, and capability a task needs.

People use Claude for long-form writing and editing, summarizing and questioning large documents, building and debugging software, and working through research problems that take several steps to resolve. Developers building on the API get extended thinking, tool use, computer use, and large context windows, letting them build agents and applications rather than just wrapping a chat interface. Claude Code extends this into the terminal, where it can read a codebase, make edits across files, run commands, and manage git workflows on a developer's behalf.

What sets Claude apart is Anthropic's emphasis on safety research and constitutional AI as the basis for how the models are trained and aligned, alongside strong performance on coding and long-context reasoning tasks. It competes directly with OpenAI's ChatGPT and Google's Gemini, and has become particularly popular among software engineers for its coding ability and among enterprises for its API and Claude Code offerings.