Chapter 1: Understanding Application Architecture: An Overview

Overview

This chapter provides a broad overview of the different types of application architecture, including the advantages and disadvantages of each. It examines single-tier, two-tier, three-tier, and n-tier applications and describes how they fit into a modern enterprise. Then this chapter covers these architectures from a traditional point of view and showcases these application architectures with an emphasis on distributed applications. This includes a discussion of each of the application layers (presentation, business, and data) and how they interact with each other across network boundaries. Finally, the chapter throws the Microsoft .NET Framework into the mix and displays the power that this new development framework provides developers. This serves as an introduction to the application architecture you will be creating throughout the rest of the book.

Note

For those developers who are already comfortable with these concepts, you can skim this chapter and move on to Chapter 2, "Building an N-Tier Application," where you will create the infrastructure of the application used throughout this book.

An architecture is the overall design of an application; it directly impacts how an application is coded. The different architecture types serve different purposes. Some architectures are for single users, and others are for a number of users in a shared environment. Not all applications need to use an n-tier architecture just because it is the buzzword of the day. There are ample reasons to use a two-tier architecture, which is a perfectly acceptable solution. What follows is a brief explanation of each tier, when to use them, and why to be cautious when making this decision.