真(zhen)(zhen)空(kong)(kong)(kong)，這(zhe)一術語譯自拉丁文vacuo，其(qi)意義是虛無。其(qi)實(shi)真(zhen)(zhen)空(kong)(kong)(kong)應理解(jie)為(wei)氣(qi)(qi)體較稀(xi)薄(bo)(bo)的(de)(de)空(kong)(kong)(kong)間。在指定的(de)(de)空(kong)(kong)(kong)間內，低(di)于一個(ge)大氣(qi)(qi)壓(ya)力的(de)(de)氣(qi)(qi)體狀(zhuang)態(tai)統稱(cheng)(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀(zhuang)態(tai)下氣(qi)(qi)體稀(xi)薄(bo)(bo)程度(du)(du)稱(cheng)(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)度(du)(du)（degreeofvacuum），通(tong)常用壓(ya)力值表(biao)示(shi)。因此真(zhen)(zhen)空(kong)(kong)(kong)包裝實(shi)際上不是完全真(zhen)(zhen)空(kong)(kong)(kong)的(de)(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)包裝技(ji)術包裝的(de)(de)食(shi)品容器內的(de)(de)真(zhen)(zhen)空(kong)(kong)(kong)度(du)(du)通(tong)常在600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)包裝稱(cheng)(cheng)為(wei)減壓(ya)包裝或排氣(qi)(qi)包裝。