What ResourceQuota.status.used shows? isn't limits.cpu used and requests.cpu used the same?

While status.hard contains the quotas defined in the spec (and represents constraints at the namespace level), I’m not able to comprehend the values from status.used, why limits.cpu(7200m) and requests.cpu(220m) are different , their hard limits may or may not be different but the usage must be same right? In my opinion there must not be limits.cpu used and requests.cpu used, just cpu used will be fine. It’s actually confusing.

    "status": {
        "hard": {
            "limits.cpu": "18",
            "limits.memory": "20Gi",
            "requests.cpu": "6",
            "requests.memory": "20Gi",
        "used": {
            "limits.cpu": "7200m",
            "limits.memory": "9092Mi",
            "requests.cpu": "220m",
            "requests.memory": "1780Mi",