1-Tier Architecture
- Mainframe with dumb terminals
- All processing takes place on the mainframe
- Presentation to user on dumb terminal
- No distributed code or data
- Business Logic on the Server
2-Tier Architecture
- Application or Database Server with a "fat" client
a.k.a. Client-Server
- Code exists on the Client, Data/Business Logic on the server.
- Code is not centralized
Business Logic on the Client
3-Tier Architecture (a.k.a. n-Tier)
- Client-Application Server-Database Server
- Could be more complicated
(ex.)Client-Web Server-EJB Server-Middleware Server-Application
Server-Database Server
- Code is distributed, but Business Logic is kept in the middle layers
