ABSTRACT
Software design and construction is the heart of any software development project. This activity accounts for a major portion of the total effort required to build any software product. Because of this, software design and construction activities are divided into many parts. In Chapter 5, we saw that a good way to divide these tasks is to use layers. Thus, we have a user interface layer (presentation layer), a middle layer (business logic layer), and a database layer. We discussed the user interface layer in Chapter 6; here, we discuss the middle layer. The database layer is discussed in Chapter 8.
