Patricia Harris Ph.D. 
What Are Programs and Applications? [PDF ebook] 

When gamers want to play a video game, they don’t have to write every line of code while doing so. In this book, readers learn why. Programs and applications can be made with pre-written code, already bundled for easy use. Readers learn how programs and applications are created. An integral part of this process is learning how different sections of code can be packaged together. Many elementary readers already know how to use computer programs and applications, but what’s behind that icon on the computer screen? This book uses manageable text and enlightening visuals to guide budding coders in discovering the answer.