真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)，這(zhe)一術(shu)語譯(yi)自拉(la)丁文vacuo，其(qi)意義(yi)是虛無。其(qi)實(shi)(shi)真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)應(ying)理解為(wei)氣體較稀薄的(de)(de)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)間(jian)。在(zai)指(zhi)定(ding)的(de)(de)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)間(jian)內(nei)，低于(yu)一個大氣壓力的(de)(de)氣體狀態統稱(cheng)為(wei)真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)。真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)狀態下氣體稀薄程度(du)稱(cheng)為(wei)真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通常用(yong)壓力值表示。因(yin)此真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)包裝(zhuang)實(shi)(shi)際上不是完全真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)的(de)(de)，采(cai)用(yong)真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)包裝(zhuang)技術(shu)包裝(zhuang)的(de)(de)食品(pin)容(rong)器內(nei)的(de)(de)真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)度(du)通常在(zai)600-1333Pa。所(suo)以，又(you)將真空(kong)(kong)(kong)(kong)(kong)(kong)(kong)(kong)包裝(zhuang)稱(cheng)為(wei)減壓包裝(zhuang)或排氣包裝(zhuang)。