Client-Server Architecture

1. Introduction

Client-server architecture is a model that separates tasks between service providers (servers) and service requesters (clients). This architecture is foundational in networking and has become a standard in software development.

2. Key Concepts

• **Client**: The entity that requests services or resources.
• **Server**: The entity that provides services or resources to clients.
• **Request/Response Model**: Clients send requests to servers, which process them and return responses.
• **Communication Protocols**: Standard methods (like HTTP, TCP/IP) for data exchange between clients and servers.

3. Architecture Overview

The client-server model can be categorized into several types:

1. **Two-Tier Architecture**: Direct communication between client and server.
2. **Three-Tier Architecture**: Introduces an intermediary layer (application server) between client and database server.
3. **N-Tier Architecture**: Extends the three-tier model with additional layers for scalability and management.

4. Flowchart

            graph TD;
                A[Client] -->|Request| B[Server];
                B -->|Response| A;
            

5. Code Example

Here is a simple example of a client-server interaction using Node.js and Express:

const express = require('express');
const app = express();
const port = 3000;

app.get('/api/data', (req, res) => {
    res.json({ message: 'Hello from the server!' });
});

app.listen(port, () => {
    console.log(`Server running at http://localhost:${port}`);
});
                

The client can request data from this server using an HTTP GET request.

6. Best Practices

• Use **RESTful APIs** for communication.
• Implement **security measures** like HTTPS and authentication.
• Optimize **server performance** through caching and scaling.
• Ensure **robust error handling** in client-server communication.

7. FAQ