Gymnosperms are trees whose seeds are not encased in a structure such as a fruit or nut. Most gymnosperms bear their seeds in cones, so they are also called conifers ("cone bearers"), and have thin needlelike leaves that sometimes earn them the name needleleaf. Virtually all are evergreen, meaning they shed only a portion of their needles each year. People in the wood products industry often refer to coniferous trees as softwoods.

The term "gymnosperm" means "naked seed"; the seeds are exposed to the air and can be seen in the cone or fruit without having to cut anything open.