A flower is the colored part of a plant. A flower is actually a blossom. The seeds form in the flower.
Most flowers need insects to do the pollination. This is how seeds can form. The flowers are colored to help attract insects.
People love flowers too. That’s why they also bred flowers so that they got bigger and more colorful. This breeding is called cultivation. For example, wild roses became cultivated roses.
There are flowers that contain several blossoms. The poinsettia consists of several flowers. The sunflower consists of many individual blossoms.