真(zhen)(zhen)空(kong)(kong)(kong)(kong)，這一術(shu)語譯自拉丁文vacuo，其意義是(shi)虛無。其實真(zhen)(zhen)空(kong)(kong)(kong)(kong)應理解為(wei)(wei)氣體較稀薄(bo)(bo)的空(kong)(kong)(kong)(kong)間。在指(zhi)定的空(kong)(kong)(kong)(kong)間內，低于(yu)一個大氣壓力(li)的氣體狀(zhuang)態統(tong)稱為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)(kong)狀(zhuang)態下氣體稀薄(bo)(bo)程度(du)稱為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓力(li)值表示。因此真(zhen)(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)實際上不是(shi)完全真(zhen)(zhen)空(kong)(kong)(kong)(kong)的，采用真(zhen)(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)技(ji)術(shu)包裝(zhuang)的食品容器(qi)內的真(zhen)(zhen)空(kong)(kong)(kong)(kong)度(du)通常在600-1333Pa。所以(yi)，又將真(zhen)(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)稱為(wei)(wei)減壓包裝(zhuang)或(huo)排氣包裝(zhuang)。