真(zhen)(zhen)空(kong)(kong)，這一(yi)術(shu)語(yu)譯(yi)自拉丁文vacuo，其(qi)意義是虛無。其(qi)實真(zhen)(zhen)空(kong)(kong)應理(li)解為(wei)(wei)氣(qi)體(ti)(ti)較稀薄的空(kong)(kong)間(jian)。在(zai)指(zhi)定的空(kong)(kong)間(jian)內，低(di)于一(yi)個大(da)氣(qi)壓力(li)(li)的氣(qi)體(ti)(ti)狀態(tai)統(tong)稱(cheng)為(wei)(wei)真(zhen)(zhen)空(kong)(kong)。真(zhen)(zhen)空(kong)(kong)狀態(tai)下氣(qi)體(ti)(ti)稀薄程度(du)稱(cheng)為(wei)(wei)真(zhen)(zhen)空(kong)(kong)度(du)（degreeofvacuum），通常(chang)用(yong)壓力(li)(li)值表示(shi)。因此真(zhen)(zhen)空(kong)(kong)包裝實際上不是完全真(zhen)(zhen)空(kong)(kong)的，采用(yong)真(zhen)(zhen)空(kong)(kong)包裝技術(shu)包裝的食(shi)品容器內的真(zhen)(zhen)空(kong)(kong)度(du)通常(chang)在(zai)600-1333Pa。所以，又(you)將(jiang)真(zhen)(zhen)空(kong)(kong)包裝稱(cheng)為(wei)(wei)減壓包裝或排氣(qi)包裝。