This chapter provides an introductory description of the program interface, that is, the tools available to the user for interacting with the program. Specifically, it will clarify how the commands are structured and how to enter data or retrieve information from the program. Many of the commands described below are common to all Windows applications, such as opening a menu or closing a window, and therefore you will most likely already be familiar with them. However, it is helpful to read the chapter to familiarize yourself with some technical terms that will be referred to throughout the manual.