The Model Context Protocol (MCP) is an open standard by Anthropic that enables AI assistants and agents to connect with external tools, APIs, and data sources through a unified interface. The ecosystem has grown explosively since its November 2024 launch — thousands of MCP servers now exist across browser automation, databases, cloud infrastructure, DevOps, productivity, security, and dozens of other domains, turning any service with an API into an AI-accessible tool. The key mental model is that each MCP server acts as a bridge between an LLM and a specific external system, exposing structured tools (functions the model can call), resources (data the model can read), and prompts (templates for common tasks) — so the most important decision is not which AI you use, but which MCP servers you connect it to.