"There are two sides to every story." This is an adage that suggests different people can see the same situation in very different ways. Their perspective can be influenced by their opinions, background, previous knowledge, and awareness of facts about the situation. In reality, there are many sides to most stories.
Presenting a comprehensive examination of a topic requires consulting sources that present different perspectives.
To write about the history and influence of a company, Microsoft for example, using only the company's own reports (10K reports, reports to shareholders, press releases, web pages, etc.) would provide just one perspective on its history. Consulting other reports that assessed Microsoft's value as an investment over time, articles in journals analyzing cases brought against or by the company, and articles in technical journals or trade magazines reporting on views of the company's dominance would be important for gaining a 360 degree view of the company.