This document shows a 3-tier architecture for a web application with presentation, business logic, and data layers separated across different servers. A browser on a desktop PC accesses application code on an application server through a gateway server over a corporate network. The application server contains business logic code and connects to a database server for the data layer.

1. Desktop PC Desktop PC
Tier 1 – Presentation
Browser Browser
Code Code layer
Corporate Network (TCP/IP)
public Internet
Application
Code
Gateway Server
Browser
Code Tier 2- Application Server
Business
Logic
layer Tier 3- Data
layer