Answer: Client/Server Computing vs N-Tiered Architecture

1. Client/Server Computing

Client/Server (C/S) computing is a distributed architecture in which the application is divided mainly into a client and a server. The client requests a service and the server processes the request and returns the result.

+---------+       Request       +---------+
| Client  | ------------------> | Server  |
| (UI)    | <------------------ |         |
+---------+       Response      +---------+

Client

• Provides the user interface.
• Accepts input from the user.
• Sends requests to the server.
• Displays the result returned by the server.

Server

• Receives client requests.
• Processes application/business operations.
• Accesses databases or other resources.
• Sends the result back to the client.

2. N-Tiered Architecture

N-tier architecture divides an application into multiple logical tiers, with each tier having a specific responsibility. A common example is three-tier architecture.

+-----------------------+
|   Presentation Tier   |
| HTML / CSS / Browser  |
+-----------+-----------+
            |
            v
+-----------------------+
|   Business Tier       |
| Application Logic     |
+-----------+-----------+
            |
            v
+-----------------------+
|      Data Tier        |
| Database / Data Access|
+-----------------------+

Presentation Tier

Handles interaction with the user. Examples include HTML, CSS, JavaScript and the web browser.

Business Logic Tier

Contains application rules and processing such as validation, authentication and calculations.

Data Tier

Handles storing, retrieving and managing data using databases and data-access components.

3. Comparison

Client/Server	N-Tier Architecture
Usually has two major parts: client and server.	Divides the application into multiple logical tiers.
Business logic may be placed in the client or server.	Business logic normally has a dedicated tier.
Simpler architecture.	More structured architecture.
Less suitable for very large applications.	Better suited for large and complex web applications.
Maintenance can become difficult when responsibilities are mixed.	Easier maintenance because responsibilities are separated.
Scaling can be more difficult.	Individual tiers can be scaled independently.

4. Advantages of N-Tier Architecture

1. Separation of concerns: Each tier performs a specific responsibility.
2. Maintainability: Changes in one tier have less impact on other tiers.
3. Scalability: Individual tiers can be scaled according to demand.
4. Security: Sensitive data and database access can be isolated in lower tiers.
5. Reusability: Business and data-access components can be reused by different clients.

Conclusion

Client/Server computing provides a simple distributed model in which clients communicate directly with servers. N-tier architecture extends this idea by separating presentation, business logic and data management into independent tiers. Therefore, N-tier architecture provides better scalability, maintainability, security and flexibility for modern web applications.