真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)，這一(yi)術語譯自拉丁文vacuo，其意義是虛(xu)無。其實(shi)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)應理(li)解為(wei)(wei)氣體較稀(xi)薄(bo)(bo)的空(kong)(kong)(kong)(kong)(kong)間(jian)。在指定的空(kong)(kong)(kong)(kong)(kong)間(jian)內，低于一(yi)個(ge)大氣壓力的氣體狀態統稱為(wei)(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)。真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)狀態下氣體稀(xi)薄(bo)(bo)程度稱為(wei)(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)度（degreeofvacuum），通(tong)常(chang)用壓力值表示。因此真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)實(shi)際(ji)上不是完(wan)全真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)的，采(cai)用真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)技術包裝(zhuang)的食品容器(qi)內的真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)度通(tong)常(chang)在600-1333Pa。所(suo)以，又(you)將真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)稱為(wei)(wei)減壓包裝(zhuang)或排氣包裝(zhuang)。