Claude Explained

kc@example.com (kc kim) — Fri, 07 Nov 2025 11:51:00 +0900

Overview

Claude is part of the artificial intelligence (AI) language model (LLM) family and was developed by the U.S. AI research company Anthropic.
It was first released in March 2023 and has since evolved through several versions, including Claude 2, Claude 3, and Claude 4.
One development goal is safety and responsible AI use, and for this it adopts the “Constitutional AI” approach.
The name Claude comes from Claude Shannon, the French mathematician and pioneer of information theory.
Like ChatGPT, it is a conversational AI model that performs text-based conversation, summarization, translation, code writing, document analysis, and more.

Version	Release period
Claude 1 (initial)	Early 2023	Basic release.
Claude 2	July 2023	Improved performance and response length.
Claude 3 family (Opus, Sonnet, Haiku)	2024	Model lineup by performance and speed. More diversified by use case.
Claude 4 family (for example, Opus 4, Sonnet 4.5)	2025	Strong for advanced tasks such as code generation.

Designed to perform many tasks such as natural language conversation, code generation, data analysis, and image input processing.
Recent versions have a much larger context window, making them stronger at handling long context and solving complex problems. For example, Claude Sonnet 4.5 improved input/output token pricing and context window characteristics.
Practical use is also considered, including APIs for developers and enterprise customers, agent usage, and tool integration.

Focus on safety and transparency
- Focuses on avoiding harmful answers and providing reasonable, explainable responses.
Long context processing
- The Claude 3 series can understand up to 200,000 tokens, about 150-200 pages, making it strong for analyzing long documents.
Intuitive conversation
- It has strong language ability in naturally understanding the user’s intent and nuance.
Enterprise API support
- Supports workflow automation and document processing through integrations with Slack, Notion, Zapier, and more.

Category	ChatGPT (OpenAI)	Claude (Anthropic)
Developer	OpenAI	Anthropic
Representative models	GPT-4, GPT-5	Claude 3 series
Philosophy	Efficiency and accuracy focused	Safety and human-centered design
Strengths	Code writing, many integrations	Document understanding, ethical control
Context length	About 128k tokens (GPT-4 Turbo)	About 200k tokens (Claude 3)

Companies use it for coding automation, document summarization, data analysis, chatbot responses, and more. It is also mentioned for code refactoring and bug fixing.
General users can also have natural conversations through web and mobile chat interfaces.
It is preparing to enter the Korean market, and cooperation with Korean companies and policy organizations is also underway.

It is not yet a “complete artificial intelligence” (AGI) or a self-aware system, and errors or false information (“hallucinations”) may occur. For example, cases have been reported where a model generated incorrect legal citations.
For corporate or organizational use, licensing, data security, and regulatory compliance are important.
Safety and ethical considerations are required from companies and developers, and access restrictions for companies in certain countries are also being discussed.

Korean input and output are possible, but response quality may be somewhat lower than in native-language environments such as English, so review is needed for important work.
Although entry into the Korean market is planned, a domestic specialized version or full localization may not yet be complete.
Depending on the purpose of use, it may be divided into free or paid plans, and APIs may incur costs.