真空(kong)(kong)(kong)(kong)(kong)，這一術語譯自(zi)拉丁(ding)文vacuo，其(qi)意義是虛無(wu)。其(qi)實(shi)真空(kong)(kong)(kong)(kong)(kong)應理(li)解為(wei)(wei)氣(qi)體較稀薄的(de)空(kong)(kong)(kong)(kong)(kong)間。在指定的(de)空(kong)(kong)(kong)(kong)(kong)間內(nei)，低于(yu)一個(ge)大(da)氣(qi)壓(ya)力的(de)氣(qi)體狀態統稱(cheng)為(wei)(wei)真空(kong)(kong)(kong)(kong)(kong)。真空(kong)(kong)(kong)(kong)(kong)狀態下氣(qi)體稀薄程度稱(cheng)為(wei)(wei)真空(kong)(kong)(kong)(kong)(kong)度（degreeofvacuum），通(tong)常用(yong)壓(ya)力值表(biao)示。因此真空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)實(shi)際上不是完(wan)全真空(kong)(kong)(kong)(kong)(kong)的(de)，采(cai)用(yong)真空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)技術包裝(zhuang)的(de)食品容器內(nei)的(de)真空(kong)(kong)(kong)(kong)(kong)度通(tong)常在600-1333Pa。所(suo)以，又將真空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)稱(cheng)為(wei)(wei)減壓(ya)包裝(zhuang)或(huo)排氣(qi)包裝(zhuang)。