The key difference between angiosperms and gymnosperms is how their seeds are developed. The seeds of angiosperms develop in the ovaries of flowers and are surrounded by a protective fruit. Gymnosperm seeds are usually formed in unisexual cones, known as strobili, and the plants lack fruits and flowers.
Angiosperm seeds develop in the ovaries of flowers and are covered with a protective fruit. Gymnosperm seeds are typically formed in something called strobili, and the plants doesn't have fruit and flowers.