The term business cycle or economic cycle refers to economy-wide fluctuations in production or economic activity over several months or years, around a long-term growth trend. It typically involves shifts over time between periods of relatively rapid economic growth (expansion or boom), and periods of relative stagnation or decline (contraction or recession).

In economic theory, imperfect competition is the competitive situation in any market where the conditions necessary for perfect competition are not satisfied. It is a market structure that does not meet the conditions of perfect competition.