Could you explain the difference between an MCP client and an MCP server, and describe the components of an MCP?

MCP (Model Context Protocol) is a lightweight protocol that enables a language model to exchange context with external services. The protocol defines a request/response schema, authentication, and transport details. The MCP client is the component that runs on the application side. It collects user input, serializes it into the MCP request format, sends it over HTTP or gRPC, and then deserializes the response. The client is typically stateless, handles retries, and may orchestrate multiple calls to different services. The MCP server, on the other hand, hosts the LLM or a wrapper around it. It receives the request, deserializes the context, runs inference, and streams back the result. The server maintains model state, caches, and can enforce rate limits. Key components of an MCP system include: 1) Context Store – a database or in‑memory cache that holds conversation history or external facts; 2) Request/Response Schema – JSON or protobuf definitions that standardize the payload; 3) Authentication & Authorization – tokens or certificates to secure the channel; 4) Transport Layer – HTTP/2 or gRPC for low‑latency communication; 5) Orchestration Layer – optional microservice that routes requests to the correct model instance. The main difference is that the client initiates and formats the request, while the server processes the request, runs the model, and returns the answer. This separation allows scaling the server independently and reusing the same client logic across multiple models.