A product is an item offered for sale that can be physical or virtual. It has a life cycle and may need to be adapted over time to remain relevant. A product needs to serve a purpose, function well, and be effectively communicated to users. It also requires a name to help it stand out.
A product hierarchy has multiple levels from core needs down to specific items. These include the need, product family, class, line, type, and item or stock keeping unit.
Products go through a life cycle with stages of development, introduction, growth, maturity, and decline. Marketing strategies must adapt to each stage such as heavy promotion and price changes in introduction and maturity.