A complete flower is a structure that is made up of four different parts namely sepals, petals, stamens and carpel which are arranged in four whorls.
Sepals are the outermost whorl of a flower or calyx of tiny green-leaf like structures.
Petals are the second whorl or corolla that are arranged next to the calyx.
Stamens are the male reproductive part of a flower consisting of two main parts— hair-like filaments and a broad sac-like anther at its tip.
Carpel is the female reproductive part of a plant that consists of three parts- an ovary at the base, a narrow thread-like style, and a terminal stigma.