This report provides a detailed analysis of the Global Financial Crisis (GFC) that began in 2007, tracing its origins to the collapse of the US mortgage market and the subsequent failure of Lehman Brothers in 2008. It delves into the causes of the crisis, including the role of rating agencies, securitization of loans, bad economic assumptions, and monetary policies. The report examines the impact of the GFC on various countries, categorizing the effects on developing, underdeveloped, and developed nations, with specific examples such as the impact on Australia. Furthermore, it discusses the measures taken by the International Monetary Fund (IMF) to address the crisis, including the creation of a crisis firewall and stepping up crisis lending. The report concludes by summarizing the key factors that led to the GFC and the global responses to mitigate its effects.