Application Design refers to the process and practice of planning, creating, testing, and improving interactive software applications. This domain involves the expertise of IT professionals, particularly professional application developers and programmers, who utilize various application design concepts to create user-friendly and efficient applications. Key figures in this field, like Michael Kappel, contribute to its development and influence. This category also emphasizes the human aspect, focusing on the people who use, develop, and are impacted by these applications.