three tier And Two Tier Applications Diffrences

A web-application is a three-tier application. This has

* Browser: Monitors data -> monitoring is done using html, dhtml, xml, JavaScript

* Web server: Manipulates data -> manipulations are done using programming languages or scripts like adv java, asp, jsp, vbscript, JavaScript, Perl, cold fusion, php

* Database server: Stores data -> data storage and retrieval is done using databases like oracle, sql server, Sybase, MySQL.

The types of tests, which can be applied on this type of applications, are:
1. User interface testing for validation & user friendliness
2. Functionality testing to validate behaviors, i/p, error handling, o/p, manipulations, services levels, order of functionality, links, content of web page & backend coverage’s
3. Security testing
4. Browser compatibility
5. Load / stress testing
6. Interoperability testing
7. Storage & data volume testing

A client-server application is a two-tier application. This has

* Forms & reporting at front-end: Monitoring & manipulations are done -> using vb, vc++, core java, c, c++, d2k, power builder etc.
* Database server at the backend: Data storage & retrieval -> using ms access, sql server, oracle, Sybase, MySQL, quad base etc.

The tests performed on these applications are:
1. User interface testing
2. Manual support testing
3. Functionality testing
4. Compatibility testing
5. Intersystem testing