真(zhen)空(kong)(kong)(kong)(kong)(kong)，這一術(shu)語譯自拉丁文vacuo，其(qi)意(yi)義(yi)是(shi)虛(xu)無。其(qi)實(shi)真(zhen)空(kong)(kong)(kong)(kong)(kong)應理解為(wei)氣體(ti)(ti)較稀薄的(de)空(kong)(kong)(kong)(kong)(kong)間(jian)。在指定的(de)空(kong)(kong)(kong)(kong)(kong)間(jian)內(nei)(nei)，低于一個(ge)大氣壓力的(de)氣體(ti)(ti)狀(zhuang)態統(tong)稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)(kong)狀(zhuang)態下氣體(ti)(ti)稀薄程(cheng)度稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)(kong)(kong)度（degreeofvacuum），通常用(yong)壓力值(zhi)表(biao)示。因此真(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)(zhuang)實(shi)際上不是(shi)完全真(zhen)空(kong)(kong)(kong)(kong)(kong)的(de)，采用(yong)真(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)(zhuang)技術(shu)包裝(zhuang)(zhuang)的(de)食品容器(qi)內(nei)(nei)的(de)真(zhen)空(kong)(kong)(kong)(kong)(kong)度通常在600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)(zhuang)稱(cheng)為(wei)減(jian)壓包裝(zhuang)(zhuang)或排氣包裝(zhuang)(zhuang)。