A product life cycle is the amount of time a product goes from being introduced into the market until it's taken off the shelves. Understanding a product’s life cycle helps businesses make decisions regarding a product’s pricing and promotion, as well as whether to expand or cut a product. There are four general stages of a product’s life cycle: introduction, growth, maturity, and decline. Business owners track each of these stages carefully in order to find opportunities to gain competitive advantage over their peers.