真(zhen)(zhen)(zhen)空(kong)(kong)，這一術語譯自拉丁(ding)文vacuo，其意義(yi)是(shi)虛無。其實(shi)(shi)真(zhen)(zhen)(zhen)空(kong)(kong)應理(li)解為氣(qi)(qi)體較稀(xi)薄的空(kong)(kong)間(jian)。在指定的空(kong)(kong)間(jian)內(nei)，低于一個大氣(qi)(qi)壓(ya)力的氣(qi)(qi)體狀態統稱為真(zhen)(zhen)(zhen)空(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)狀態下(xia)氣(qi)(qi)體稀(xi)薄程度(du)稱為真(zhen)(zhen)(zhen)空(kong)(kong)度(du)（degreeofvacuum），通常用壓(ya)力值表示。因此(ci)真(zhen)(zhen)(zhen)空(kong)(kong)包(bao)(bao)裝(zhuang)實(shi)(shi)際上不是(shi)完(wan)全真(zhen)(zhen)(zhen)空(kong)(kong)的，采用真(zhen)(zhen)(zhen)空(kong)(kong)包(bao)(bao)裝(zhuang)技術包(bao)(bao)裝(zhuang)的食(shi)品容器(qi)內(nei)的真(zhen)(zhen)(zhen)空(kong)(kong)度(du)通常在600-1333Pa。所以，又將真(zhen)(zhen)(zhen)空(kong)(kong)包(bao)(bao)裝(zhuang)稱為減壓(ya)包(bao)(bao)裝(zhuang)或排氣(qi)(qi)包(bao)(bao)裝(zhuang)。