Origins: How and when did the subject first emerge? Why? Who was involved? What were their motivations? What was the status quo before the emergence of the subject?
Evolution: How do earlier incarnations of the subject compare to its form today? What are the major or most interesting milestones in its development? What were the challenges encountered during its development? How might it evolve in the future?
Impact: How is the subject relevant to your reader, your audience? How did the subject enable developments in other fields of knowledge? How did the subject affect todays diversity of applications of the computer? How did the subject impact individuals or organizations? What is the importance of the subject to branches of computer science? How did the subject affect various spheres of human activity? What are the advantages and disadvantages of its impact?
