Gymnosperms are a group of seed-producing plants that include conifers, cycads, ginkgo, and gnetophytes. Unlike angiosperms, which bear seeds within fruits, gymnosperms produce seeds that are exposed on cones or other structures. They are characterized by their needle-like leaves, woody stems, and ability to thrive in various environments. Gymnosperms play a crucial role in ecosystems and are significant for timber and resin production.