What is Client-Server Architecture in Computer Network?

In Client-Server Architecture, a specific computer designated as a server provides various services to other computers known as clients. The server acts as a service provider, while the client acts as a service requester. When a client requests information from the server, the server processes the request and responds with the appropriate data or service.

The most common client-server arrangement is a Local Area Network (LAN) consisting of multiple microcomputers connected to a central network server that serves all clients within the network.

Types of Client-Server Architecture

Two-Tier Architecture

In two-tier architecture, there are only two components: the client and the server. The client directly communicates with the server for data and services. While this model offers simplicity, it faces scalability issues when hundreds of clients simultaneously request data from the server, causing performance bottlenecks and increased waiting times.

Three-Tier Architecture

Three-tier architecture, also known as multi-tier architecture, introduces a middle layer between the client and server. This intermediate layer acts as an application server that manages client requests and maintains a queue system. It processes and forwards requests to the database server while allowing clients to continue their work without waiting for server responses, significantly improving system performance and scalability.

Key Advantages

• Centralized management − All data and resources are managed from a central server location.

• Resource sharing − Multiple clients can access shared resources efficiently.

• Security − Centralized security policies and access control mechanisms.

• Scalability − Easy to add more clients or upgrade server capacity as needed.

Common Examples

Popular examples of client-server architecture include web browsing (browser as client, web server as server), email systems (email client and mail server), file sharing systems, and database management systems where applications act as clients accessing database servers.

Conclusion

Client-server architecture provides a structured approach to network computing where dedicated servers provide services to multiple clients. The three-tier model offers better scalability and performance compared to the simpler two-tier architecture, making it suitable for enterprise-level applications.