Both gymnosperms and angiosperms bear seeds, then why are they classified separately?

Explanation

Gymnosperms and angiosperms are classified separately because of the following reasons :
1. The ovules of gymnosperms are naked. But in angiosperms, they are enclosed inside the ovary.
2. In gymnosperms, the wood is non-porous, i.e., the vessels are absent. In angiosperms, the wood is porous, i.e., the vessels are present.
3. The archagonia are absent in angiosperms whereas they are present in gymnosperms.