Flowering plants sprout with either one or two seed leaves. If one, the plant is a monocotyledon, or, monocot, for short. Two leaves make the plant a dicot or dicotyledon. While roots grow down, vegetative matter grows up, including stems and more leaves. Eventually, there is enough growth and maturity that the plant is ready for the next stage.
Biennials and Perennials
If the plant lives for two growth seasons---a biennial---when winter or dormancy approaches, the plant creates food storage organs. These are the bulbs, corms and tubers from which new vegetative growth comes in the next active growing season. The plant might look as if it has died, the vegetative growth dying off, though the plant is only resting. Perennials (plants that live longer than two seasons) can behave similarly, except they don't produce food storage organs. During dormancy, perennials can lose their green growth to dry or cold periods. Evergreens keep their leaves.
When a flowering plant is ready to reproduce, it must produce sexual organs for the purpose. Those sexual organs are flowers. Biennials have their flowering stage in their second and final growing season, annuals have it during their first and only growing season and perennials may wait years before they begin to flower, then do so every year until the end of their lives. The flowers produce "male" pollen that will be carried by wind or creature to the "female" part of a flower. If pollination is successful, sperm meets egg within the ovary of the flower, which is contained within a flower's pistil. A second sperm joins with nuclei found within the embryonic sac of the ovary.
Seed and Fruit
After pollination, a flowering plant spends its energy creating seed and fruit. The joined egg and sperm form a zygote, while the sperm fused with the nuclei create an endosperm. The zygote and endosperm end up as a seed, the zygote now an embryonic form of a plant, the endosperm providing food the new plant will use as it emerges from seed. Meanwhile, the ovary of the flower ripens into fruit.
After the fruiting stage, both biennials and annuals enter the end stage of their lives. The vegetative growth dies. If reproduction was successful, new life will come from seed. Perennials might continue to grow for many years. These include woody plants like roses and trees. Some flowering plants live hundreds of years before succumbing to disease, pests or old age.