The document defines recessions and depressions, describing recessions as lasting 6-18 months and involving a decline in GDP over two consecutive quarters, while depressions are longer term declines in GDP that have more severe economic impacts. It discusses the types of recessions, including V-shaped, W-shaped, and L-shaped recessions defined by the pattern of economic decline and recovery. Causes of recessions include deflation, overinvestment, and reduced consumer confidence, while consequences are higher unemployment, falling incomes, and decreased tax revenue. The Great Recession of the late 2000s/early 2010s is examined as the most significant recession in recent decades, caused by the subprime mortgage crisis and housing market collapse in the