Metadata sent with HTTP requests and responses that controls behavior such as caching, security policies, and content handling. Common examples include Cache-Control, Content-Security-Policy, and Strict-Transport-Security.

A local MCP server is an MCP server that runs on the same machine as the MCP host, usually for low-latency access to local files, apps, or developer tools.

A remote MCP server is an MCP server reached over a network instead of running locally, often requiring explicit authentication and a defined transport.

A hosted MCP server is a remote MCP server operated by a provider, letting an MCP client connect to tools or data without installing the server locally.

MCP authentication is the process of verifying identity when an MCP client connects to a remote MCP server, usually before permissions or tool access are granted.