真(zhen)(zhen)空(kong)(kong)(kong)，這一術語譯自拉丁文(wen)vacuo，其意義是(shi)虛(xu)無(wu)。其實真(zhen)(zhen)空(kong)(kong)(kong)應理解為氣(qi)體(ti)較稀薄(bo)的(de)空(kong)(kong)(kong)間(jian)。在(zai)(zai)指定(ding)的(de)空(kong)(kong)(kong)間(jian)內，低(di)于(yu)一個大氣(qi)壓(ya)(ya)力的(de)氣(qi)體(ti)狀態統稱為真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀態下氣(qi)體(ti)稀薄(bo)程度(du)稱為真(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓(ya)(ya)力值表示(shi)。因此真(zhen)(zhen)空(kong)(kong)(kong)包裝(zhuang)(zhuang)(zhuang)實際(ji)上不是(shi)完全(quan)真(zhen)(zhen)空(kong)(kong)(kong)的(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)包裝(zhuang)(zhuang)(zhuang)技(ji)術包裝(zhuang)(zhuang)(zhuang)的(de)食品容(rong)器內的(de)真(zhen)(zhen)空(kong)(kong)(kong)度(du)通常在(zai)(zai)600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)包裝(zhuang)(zhuang)(zhuang)稱為減壓(ya)(ya)包裝(zhuang)(zhuang)(zhuang)或排氣(qi)包裝(zhuang)(zhuang)(zhuang)。