When you're talking about something as vast as the Great Financial Crisis that led to a monetary policy with no historical precedent (still in effect btw), you

When you're talking about something as vast as the Great Financial Crisis that led to a monetary policy with no historical precedent (still in effect btw), you simply cannot summarize it in an article. It is simply Too Big To Describe, to paraphrase the favorite mantra of the era. I've noted certain articles and books in another comment above. Those should help get up to speeed.