What Claude is, and which plan to use

Claude is an AI assistant made by Anthropic. You mainly use it as a chat assistant at claude.ai (plus desktop and mobile apps), where you type a request and Claude responds. It's widely praised for natural writing, careful reasoning, and working with long documents. This lesson gets you oriented on the models and plans — teaching the durable logic so you're not lost when specifics change.

The model tiers (durable logic). Claude comes in a family of models, and Anthropic uses a consistent naming pattern worth learning:

• Opus — the most capable model, for complex, demanding work.
• Sonnet — the balanced everyday workhorse (great speed-and-intelligence tradeoff).
• Haiku — the fastest, most efficient model.

The number after the name (e.g., Opus 5, Sonnet 5, Haiku 4.5) is the generation — and those change every few months. So learn the tier logic (Opus = most capable, Sonnet = balanced, Haiku = fastest) rather than memorizing version numbers, which are the single most volatile detail. (Verify the current model names on Anthropic's site.)

The plans (verify current — prices and details shift). Claude has a free tier and paid tiers:

• Free — chat on all apps, web search, Artifacts, voice, memory, connectors, file creation, and more, using the faster models (not Opus).
• Pro (~$20/mo) — more usage, access to the most capable models, unlimited Projects, deeper Research, and power-user tools.
• Max — much higher usage limits (5x or 20x Pro), for heavy users.
• Team / Enterprise — for organizations, with admin controls and, importantly, no training on your content by default (a data-privacy plus for business use).

Usage is limited by rolling time windows (not a fixed message count) and depends on message length, model, and features. (Verify current plans and limits — they change.)

How to pick. Start on Free to learn Claude — it's genuinely capable. Upgrade to Pro when you hit usage limits or want the most capable models, Projects, and Research. Consider Team/Enterprise for organizational or sensitive work (better data protections). Most people start free and upgrade only when they feel a real limit.

The takeaway: Claude is Anthropic's AI assistant (web, desktop, mobile), praised for writing, reasoning, and long documents. Learn the durable model-tier logic — Opus (most capable), Sonnet (balanced everyday), Haiku (fastest) — rather than memorizing version numbers, which change every few months. The plans: Free (capable, faster models), Pro (~$20/mo, more usage + top models + Projects + Research), Max (heavy usage), and Team/Enterprise (org controls and no-training-by-default for business). Usage is time-window-limited, not a fixed message count. Start free to learn, upgrade when you hit a real limit or need top models, and use business tiers for sensitive work. Verify current model names, plans, and prices — they're the most volatile details.