Despite the name, Applications are not what we normally think of as software applications. They are reusable units of code that are bigger than modules. In fact, they most often contain multiple modules. They’re similar in scale to libraries in other ecosystems. While they can function as libraries, they can also be so much more.
Applications can act as true building blocks for our programs, a means of putting together integral pieces of business logic to build a larger whole. Working with larger building blocks like these makes us really productive.
Applications can also stand on their own as what we traditionally think of as an application. The IslandsEngine Application we developed in the first part of the book is one example. ...