Answer: A recession
The business cycle is the name given to the rise and fall in production output in goods. This is usually measured in terms of GDP.
A peak represent the best moment in output of a particualr good or service after a period of expansion. Expansion was traditionally associated with population growth and the rise of consumerism. More recently, expansion is associated with debt from credit cards, mortgages and loans. After this expansion reaches a peak, it is usually followed by a period of recession.