Blogging and wiki applications, along with many Web applications, are designed by using what is known as a three-tiered architecture, in which each tier, or functional component, is responsible for one of these specific processing tasks. Discuss the three tiers.

Question

What will be an ideal response?

Answer 1

The presentation tier deals with the presentation of information in the browser and the experience of users working with that information. It handles all aspects of displaying the user interface and processing any keystrokes or mouse clicks. The presentation tier may handle content that includes HTML-formatted text, images, and hyperlinks; forms in which the user enters information that is then sent to the server for processing; or applications that make use of presentation technologies such as JavaScript, AJAX, or Flash to provide a rich user experience within the browser. This exchange of information between client and server enables the user to interact with Web applications by using a Web browser.

The middle tier, also known as the business logic tier, is responsible for processing user input from the presentation tier, interacting with information from the database tier, and delivering the formatted information to the user's browser. The middle tier stores applications that handle any decision making and analysis of information that is retrieved from or stored in a database. The software that provides a blog or wiki's behavior resides on this tier.

The database tier is responsible for retrieving the requested information from the database. The database tier makes these results available to the application running in the middle tier for processing.