Multiple Classes and Inheritance - Semester 2 Week 8

Encapsulation - the concept of separating processing and hiding data within specific classes.

The three tier structure is divided into three tiers: Presentation, Business, and Persistence or Data Access.

Presentation Tier - contains the classes that display information for the user and accept user input.

Business Tier - contains logic and calculations that must occur in order to fulfill the requirements of the program. The classes use data entered by users and data from storage to perform the calculations.

Persistence Tier - contains code required to read and write data from storage. After the program is terminated the data gets stored in the database and therefore gets the name persistent data.