Management Economics: Define 'Business cycle'. Explain various phases of business cycle?

Introduction. The business cycle or economic cycle refers to the ups and downs seen somewhat simultaneously in most parts of an economy. The cycle involves shifts over time between periods of relatively rapid growth of output (recovery and prosperity), alternating with periods of relative stagnation or decline (contraction or recession). These fluctuations are often measured using the real gross domestic product. To call those alternances "cycles" is rather misleading, as they don't tend to repeat …

…the central idea of business-cycle literature, that the economy has regular and periodic waves--a cycle--lasting for several years, has few adherents today. Perhaps such cycles never existed, or perhaps they once did but no longer do because the government now plays an active role in the economy. However, the business-cycle approach remains useful because it is an easy way to introduce a number of macroeconomic topics, including the adjustment process that remains central in macroeconomics.