Glossary: n-Tier Architecture

What is n-Tier Architecture?

n-Tier architecture and its flexibility is what makes Java such a stand out among other languages and m-Power stand out among competitive tools.

What is n-tier architecture?

An n-tier application is one that is made up of three or more program sections called tiers. The most common example of this is the 3-tier application, which m-Power creates. 'Three-tiers' refers to the following:

• Presentation Layer: HTML layer for graphic user interface (what the application looks like to the user)
• Application Layer: Application logic that houses the application's business rules
• Database Layer: SQL statements and queries for storing, retrieving, and filtering data from the database

The architecture is flexible because each of these tiers can live apart from each other, on different machines, accessing various databases, and still function as one.

NOTE: While CGI, RPG/Web, COBOL/Web or Web-facing solutions can sometimes seem like the next logical step to the Web for someone with a more traditional development background, they become a dead-end in the future when they cannot provide this modular and platform-independent architecture to allow you to be flexible in your future development choices.

Many claim to have Java or n-tier architecture, but make sure. Ask vendors to show you the modular n-tier architecture behind the applications they build for you.

This modularized or n-tier architecture is also the backbone of many Application Modernization Roadmaps, including IBM's.