These three structures are often termed a pistil or carpel. In many plants, the pistils will fuse for all or part of their length. Like the stamen, the carpel is thought to be a modified leaf. Image from W.H. Freeman and Sinauer Associates, used by permission. The stigma functions as a receptive surface on which pollen lands and germinates its pollen tube.
Corn silk is part stigma, part style.
The style serves to move the stigma some distance from the ovary. This distance is species specific. The ovary contains one or more ovules, which in turn contain one female gametophyte, also referred to in angiosperms as the embryo sac . Some plants, such as cherry, have only a single ovary which produces two ovules. Only one ovule will develop into a seed.