真(zhen)空(kong)(kong)(kong)(kong)(kong)，這一(yi)術語(yu)譯(yi)自拉丁文vacuo，其(qi)意(yi)義是(shi)虛無。其(qi)實真(zhen)空(kong)(kong)(kong)(kong)(kong)應理解為氣體較稀薄(bo)的(de)(de)空(kong)(kong)(kong)(kong)(kong)間(jian)(jian)。在指定的(de)(de)空(kong)(kong)(kong)(kong)(kong)間(jian)(jian)內(nei)，低于一(yi)個大氣壓力(li)的(de)(de)氣體狀(zhuang)態統(tong)稱為真(zhen)空(kong)(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)(kong)狀(zhuang)態下(xia)氣體稀薄(bo)程(cheng)度(du)稱為真(zhen)空(kong)(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通常用(yong)壓力(li)值表示(shi)。因此真(zhen)空(kong)(kong)(kong)(kong)(kong)包裝實際上不是(shi)完全真(zhen)空(kong)(kong)(kong)(kong)(kong)的(de)(de)，采用(yong)真(zhen)空(kong)(kong)(kong)(kong)(kong)包裝技術包裝的(de)(de)食(shi)品容器內(nei)的(de)(de)真(zhen)空(kong)(kong)(kong)(kong)(kong)度(du)通常在600-1333Pa。所(suo)以，又將真(zhen)空(kong)(kong)(kong)(kong)(kong)包裝稱為減(jian)壓包裝或排氣包裝。