真空(kong)(kong)，這(zhe)一術(shu)語譯自拉丁(ding)文vacuo，其意義是(shi)(shi)虛(xu)無。其實(shi)真空(kong)(kong)應理(li)解為氣體較稀薄的(de)(de)空(kong)(kong)間(jian)。在指定(ding)的(de)(de)空(kong)(kong)間(jian)內，低于一個(ge)大氣壓力的(de)(de)氣體狀態統稱為真空(kong)(kong)。真空(kong)(kong)狀態下(xia)氣體稀薄程度稱為真空(kong)(kong)度（degreeofvacuum），通常(chang)用壓力值表示。因(yin)此真空(kong)(kong)包裝(zhuang)(zhuang)實(shi)際上不是(shi)(shi)完(wan)全真空(kong)(kong)的(de)(de)，采用真空(kong)(kong)包裝(zhuang)(zhuang)技術(shu)包裝(zhuang)(zhuang)的(de)(de)食(shi)品容器內的(de)(de)真空(kong)(kong)度通常(chang)在600-1333Pa。所以，又(you)將真空(kong)(kong)包裝(zhuang)(zhuang)稱為減壓包裝(zhuang)(zhuang)或排氣包裝(zhuang)(zhuang)。