The product lifecycle refers to the stages a product goes through from its initial development to its eventual decline. It typically includes five phases: development, introduction, growth, maturity, and decline. During the development phase, ideas are created and tested. Once launched, the product enters the introduction phase, where it is introduced to the market. As the product gains popularity, it enters the growth phase, where sales increase rapidly. Eventually, it reaches maturity, where sales stabilize. Finally, in the decline phase, sales decrease as newer products emerge, leading to the product's eventual withdrawal from the market.