Fruit production of apples is a two-year process, beginning with the transition of a bud from vegetative to a floral state during the summer. The bud differentiates, overwinters and emerges as a flower the following spring. Flowers are then pollinated, fertilized and the fruit grows first by cell division and later by cell enlargement. All of these processes are vital to the development of high-quality fruit. Suboptimal environmental, biological or cultural conditions during any of these stages can reduce both productivity and fruit quality. Here we discuss the biological processes and genetic controls of these developmental stages. We also highlight some of the key environmental effects and how these processes can be manipulated by cultural management.