真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)，這一術語譯自(zi)拉丁文vacuo，其(qi)意義是(shi)虛無(wu)。其(qi)實真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)應理解(jie)為(wei)(wei)氣(qi)體較(jiao)稀(xi)薄的(de)空(kong)(kong)(kong)(kong)(kong)間。在(zai)指定的(de)空(kong)(kong)(kong)(kong)(kong)間內(nei)，低于一個大氣(qi)壓(ya)力的(de)氣(qi)體狀(zhuang)態統(tong)稱為(wei)(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)狀(zhuang)態下(xia)氣(qi)體稀(xi)薄程度稱為(wei)(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)度（degreeofvacuum），通(tong)常(chang)用壓(ya)力值表示。因此真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)(zhuang)(zhuang)實際上不(bu)是(shi)完全真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)的(de)，采(cai)用真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)(zhuang)(zhuang)技術包裝(zhuang)(zhuang)(zhuang)的(de)食品容(rong)器內(nei)的(de)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)度通(tong)常(chang)在(zai)600-1333Pa。所以(yi)，又將真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)(zhuang)(zhuang)稱為(wei)(wei)減壓(ya)包裝(zhuang)(zhuang)(zhuang)或排氣(qi)包裝(zhuang)(zhuang)(zhuang)。