In plant biology, plants are, for the most part, photosynthetic eukaryotes that make up the kingdom Plantae. In their respective environments/habitats, plants use water, light energy, and carbon dioxide (these being inorganic substances) to synthesize sugar/nutrients that serve as food for various animals.
In addition to synthesizing their own food, plants in different environments (aquatic, terrestrial etc) play an important role in the production of oxygen making them essential to all life on earth. Although plant biology enables photosynthesis (a unifying characteristic), different types of plants have various physical and genetic characteristics.
As such, they are divided into distinct groups that include:
Angiosperms - Plants that produce flowers and bear fruits (over 200,000 species of plants belong to this category).
Gymnosperms - Include Seed-bearing vascular plants (these plants do not produce flowers nor bear fruit