What is MCP (Model Context Protocol)? Plain-English Definition

In more detail

MCP — Model Context Protocol — is a shared standard for connecting AI to other software. Before it, every app-to-AI hookup was custom wiring; with MCP, a tool describes its abilities once and any compatible AI can plug in and use them. A USB port for AI.

It matters because connections are what make assistants genuinely useful — reading your files, checking your calendar, querying your company’s systems. A common plug means builders write one connector instead of five, and every new AI app inherits a whole ecosystem of ready-made tools on day one.

📌 See it in action

A developer writes one MCP server for her company’s product database. Instantly, Claude can answer stock questions, another AI app can update listings, and a third can pull sales reports — three different assistants, one connector, zero custom integrations. That’s the USB-port promise in action.

Goes with

Function Calling →Agentic AI →Computer Use →

Now put the vocabulary to work.

Meet the models →Which AI is mine?