MCP, the Model Context Protocol, is a universal plug for AI. Before it, linking an AI tool to each app meant a custom build. MCP sets one shared standard, so any app that speaks MCP can connect to any AI tool that speaks MCP, a company's own systems included.
You rarely touch MCP directly; it is the plumbing under connectors. But it is why the list of apps Claude can reach keeps growing, and why you can add a custom connector by its MCP address.