A round primal cut is derived from a hindquarter and is more or less a hind leg and one half a rump. It is the second largest primal cut and commonly includes bone segments from round, hindshank, hip and tail bones.
A round primal cut sources retail cuts that are not tender (thus more robust in flavor) and also, retail cuts that are tender (thus less robust in flavor). Some cuts can be tender enough for roasting; for example, higher quality top round, knuckle, and rump roasts. However, the majority of cuts from a round primal cut are neither tender nor moist because they are derived from muscles with less fat, muscles a cow more frequently used.
A retail cut (from whichever primal) can be less desired in terms of tenderness while simultaneously, more desired both in terms of leanness and robustness in flavor.