The product life cycle has four main stages: introduction, growth, maturity, and decline. During the introduction stage, the objective is to attract early adopters with strategies like rapid or slow skimming. In the growth stage, competition increases and strategies focus on expanding distribution and product lines. The maturity stage sees sales and profits stabilize as the market becomes saturated. In decline, sales decrease due to factors like new technologies, and strategies aim to cut costs or terminate the product.