Both gymnosperms and angiosperms bear seeds, but they are classified separately based on the nature of their seeds and ovules.

In gymnosperms, the ovules are not enclosed by any ovary wall. After fertilisation, the seeds remain exposed and are therefore called naked-seeded plants. The seeds that develop are not covered.

In angiosperms or flowering plants, the pollen grains and ovules are developed in specialised structures called flowers. Unlike gymnosperms, the seeds in angiosperms are enclosed in fruits. This fundamental difference in seed protection is the basis for their separate classification.