Claude is Anthropic's family of AI models and the assistant built on them, used for writing, analysis, coding and agent work.
In plain words
Anthropic first offered Claude in March 2023 as an assistant aimed at being helpful, honest and harmless. Models come in tiers, from the fastest and cheapest up to the most capable. The current lineup is Claude Fable 5.2, Opus 5.5, Sonnet 5.5 and Haiku 5.5. All current models take text and images and can use tools. Anthropic publishes a constitution describing the values it trains Claude to follow.
A quick example
A developer building a support bot might start with Opus 5.5, as Anthropic's docs suggest, then try Haiku 5.5 for the quickest, cheapest replies once the bot works.
Where you'll meet it
- The Claude apps on web, iOS and Android.
- The Claude API and cloud platforms such as Amazon Web Services.
- Coding tools such as Claude Code.
Related
Sources
- DocsIntroducing Claude, Anthropic · read 20 Oct 2026
- DocsModels overview, Claude Platform docs · read 9 Nov 2026
- DocsClaude's Constitution, Anthropic · read 29 Sept 2026
- DocsClaude Haiku, Anthropic · read 7 Oct 2026
Checked by WhatIsAI against the sources above · 9 Nov 2026. Spotted an error? Report it.