真空(kong)(kong)(kong)，這一(yi)術語譯自拉丁文vacuo，其意(yi)義是虛無。其實(shi)真空(kong)(kong)(kong)應(ying)理解為(wei)(wei)氣(qi)(qi)體較稀(xi)薄(bo)的(de)空(kong)(kong)(kong)間。在指定的(de)空(kong)(kong)(kong)間內，低(di)于一(yi)個大(da)氣(qi)(qi)壓力的(de)氣(qi)(qi)體狀態統稱(cheng)(cheng)(cheng)為(wei)(wei)真空(kong)(kong)(kong)。真空(kong)(kong)(kong)狀態下(xia)氣(qi)(qi)體稀(xi)薄(bo)程(cheng)度稱(cheng)(cheng)(cheng)為(wei)(wei)真空(kong)(kong)(kong)度（degreeofvacuum），通(tong)(tong)常(chang)用壓力值(zhi)表示。因此(ci)真空(kong)(kong)(kong)包裝(zhuang)實(shi)際上不(bu)是完全真空(kong)(kong)(kong)的(de)，采用真空(kong)(kong)(kong)包裝(zhuang)技術包裝(zhuang)的(de)食品容器內的(de)真空(kong)(kong)(kong)度通(tong)(tong)常(chang)在600-1333Pa。所以，又(you)將(jiang)真空(kong)(kong)(kong)包裝(zhuang)稱(cheng)(cheng)(cheng)為(wei)(wei)減壓包裝(zhuang)或排氣(qi)(qi)包裝(zhuang)。