Claude is Anthropics AI assistant designed around principles of being helpful, harmless, and honest. Development: Created by Anthropic (founded by former OpenAI researchers), focused on AI safety from the start. Training approach: Constitutional AI (CAI) - model trained with explicit principles/constitution rather than pure RLHF, aims for more predictable behavior. Model family: Claude 1, Claude 2, Claude 3 (Haiku, Sonnet, Opus) with increasing capability. Key features: Long context windows (100K-200K tokens), strong reasoning, code generation, analysis, nuanced responses. Safety focus: Trained to avoid harmful outputs, acknowledge uncertainty, refuse inappropriate requests while remaining helpful. Capabilities: General knowledge, coding, analysis, writing, math, multilingual. Competitive with GPT-4. API access: Available through Anthropic API, Amazon Bedrock, Google Cloud. Differentiators: Emphasis on safety research, constitutional approach, longer context, particular strength in analysis and nuance. Use cases: Enterprise applications, coding assistants, content creation, research, customer service. Leading alternative to OpenAI models.