真(zhen)(zhen)空(kong)(kong)(kong)(kong)，這一術語譯自拉丁文(wen)vacuo，其(qi)意義是虛無。其(qi)實真(zhen)(zhen)空(kong)(kong)(kong)(kong)應理解為氣(qi)體較稀(xi)薄(bo)的(de)(de)空(kong)(kong)(kong)(kong)間。在(zai)指定(ding)的(de)(de)空(kong)(kong)(kong)(kong)間內(nei)，低于一個(ge)大氣(qi)壓(ya)力的(de)(de)氣(qi)體狀態統稱為真(zhen)(zhen)空(kong)(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)(kong)狀態下(xia)氣(qi)體稀(xi)薄(bo)程度稱為真(zhen)(zhen)空(kong)(kong)(kong)(kong)度（degreeofvacuum），通常用(yong)壓(ya)力值表(biao)示。因此真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)實際上不(bu)是完全真(zhen)(zhen)空(kong)(kong)(kong)(kong)的(de)(de)，采用(yong)真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)技術包(bao)裝(zhuang)(zhuang)的(de)(de)食(shi)品容(rong)器內(nei)的(de)(de)真(zhen)(zhen)空(kong)(kong)(kong)(kong)度通常在(zai)600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)稱為減壓(ya)包(bao)裝(zhuang)(zhuang)或排氣(qi)包(bao)裝(zhuang)(zhuang)。