In practice
It might connect to a database, file system, API or product's own data. The AI app is the client, and 1 client can connect to several servers.
Servers can run locally on your machine or remotely at a URL. Remote servers update in 1 place and need no local install. Local servers can reach files and programs on your machine that a remote server can't.
Why it matters for product builders
Before MCP, every tool needed a separate integration with every AI app. A server written once can work with any client that speaks the protocol. That helped the ecosystem grow quickly through 2025.
**Source note**
Anthropic published the [Model Context Protocol](https://modelcontextprotocol.io) as an open standard in November 2024.