A standard way for an AI to talk to tools and data. Think of it as a USB port for AI.
Before MCP, every AI tool had its own custom way of hooking into outside systems. Want Claude to read your Notion? Custom code. Want ChatGPT to use your CRM? Different custom code. MCP fixes this by defining ONE protocol. You write an MCP server once (for Notion, Gmail, your database, whatever), and any MCP-compatible AI can plug into it. Like how any USB-C device works with any USB-C port.
MCP is what turns an AI from a chat window into a hub that connects to everything you actually use. Without a standard, every integration is a one-off project. With MCP, it's a plug-in. If you want to build an autonomous system that touches real tools, MCP is how you do it.