真(zhen)空(kong)(kong)，這一術語(yu)譯(yi)自拉丁文vacuo，其意義是虛無。其實真(zhen)空(kong)(kong)應理解為(wei)(wei)氣體較稀薄(bo)的空(kong)(kong)間(jian)。在(zai)指定的空(kong)(kong)間(jian)內(nei)，低于一個大(da)氣壓力的氣體狀(zhuang)態統稱為(wei)(wei)真(zhen)空(kong)(kong)。真(zhen)空(kong)(kong)狀(zhuang)態下氣體稀薄(bo)程度稱為(wei)(wei)真(zhen)空(kong)(kong)度（degreeofvacuum），通常用壓力值表示。因此真(zhen)空(kong)(kong)包(bao)裝實際上不是完全真(zhen)空(kong)(kong)的，采用真(zhen)空(kong)(kong)包(bao)裝技(ji)術包(bao)裝的食(shi)品容器內(nei)的真(zhen)空(kong)(kong)度通常在(zai)600-1333Pa。所以(yi)，又將真(zhen)空(kong)(kong)包(bao)裝稱為(wei)(wei)減壓包(bao)裝或排(pai)氣包(bao)裝。