The document discusses the business cycle, which consists of periodic expansions, peaks, contractions, and troughs in economic activity. During an expansion, the economy grows with increasing production, employment, and business starts. A peak occurs when growth reaches its maximum, followed by a contraction where activity declines. A trough is the low point with reduced output, jobs, and new ventures, which can be considered a recession if prolonged. Standard of living, GDP, inflation, and the CPI are also covered.