真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其意義是(shi)虛無。其實真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)應(ying)理解(jie)為(wei)(wei)氣(qi)體(ti)較稀薄的空(kong)(kong)(kong)(kong)(kong)(kong)間。在指定的空(kong)(kong)(kong)(kong)(kong)(kong)間內，低于一個大氣(qi)壓力的氣(qi)體(ti)狀(zhuang)態統稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)狀(zhuang)態下(xia)氣(qi)體(ti)稀薄程(cheng)度(du)稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常用(yong)壓力值(zhi)表示。因此(ci)真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)包裝(zhuang)實際上不是(shi)完全(quan)真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)的，采用(yong)真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)包裝(zhuang)技術包裝(zhuang)的食品容器內的真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)度(du)通(tong)常在600-1333Pa。所(suo)以，又將真(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)包裝(zhuang)稱為(wei)(wei)減壓包裝(zhuang)或排氣(qi)包裝(zhuang)。