真空(kong)(kong)(kong)(kong)(kong)，這一術(shu)(shu)語譯自拉丁(ding)文vacuo，其意(yi)義是(shi)虛無。其實真空(kong)(kong)(kong)(kong)(kong)應理解為氣(qi)體(ti)較稀薄的(de)(de)空(kong)(kong)(kong)(kong)(kong)間(jian)。在指定的(de)(de)空(kong)(kong)(kong)(kong)(kong)間(jian)內，低于(yu)一個(ge)大氣(qi)壓力的(de)(de)氣(qi)體(ti)狀(zhuang)態統稱(cheng)為真空(kong)(kong)(kong)(kong)(kong)。真空(kong)(kong)(kong)(kong)(kong)狀(zhuang)態下(xia)氣(qi)體(ti)稀薄程度稱(cheng)為真空(kong)(kong)(kong)(kong)(kong)度（degreeofvacuum），通(tong)常(chang)(chang)用(yong)壓力值表(biao)示。因此真空(kong)(kong)(kong)(kong)(kong)包(bao)裝(zhuang)實際上不是(shi)完(wan)全真空(kong)(kong)(kong)(kong)(kong)的(de)(de)，采用(yong)真空(kong)(kong)(kong)(kong)(kong)包(bao)裝(zhuang)技術(shu)(shu)包(bao)裝(zhuang)的(de)(de)食品(pin)容(rong)器內的(de)(de)真空(kong)(kong)(kong)(kong)(kong)度通(tong)常(chang)(chang)在600-1333Pa。所以，又將真空(kong)(kong)(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)為減壓包(bao)裝(zhuang)或(huo)排氣(qi)包(bao)裝(zhuang)。