真(zhen)空(kong)(kong)(kong)(kong)，這一術(shu)語(yu)譯自拉丁文vacuo，其意義是虛無(wu)。其實(shi)真(zhen)空(kong)(kong)(kong)(kong)應理解(jie)為(wei)(wei)氣(qi)(qi)體較稀薄(bo)的空(kong)(kong)(kong)(kong)間。在指定(ding)的空(kong)(kong)(kong)(kong)間內(nei)，低于一個大氣(qi)(qi)壓力的氣(qi)(qi)體狀態統稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)狀態下氣(qi)(qi)體稀薄(bo)程度(du)稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常(chang)用(yong)(yong)壓力值表(biao)示。因此真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)(bao)裝(zhuang)(zhuang)實(shi)際上不(bu)是完全真(zhen)空(kong)(kong)(kong)(kong)的，采用(yong)(yong)真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)(bao)裝(zhuang)(zhuang)技術(shu)包(bao)(bao)(bao)裝(zhuang)(zhuang)的食(shi)品容器內(nei)的真(zhen)空(kong)(kong)(kong)(kong)度(du)通(tong)常(chang)在600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)(bao)裝(zhuang)(zhuang)稱為(wei)(wei)減壓包(bao)(bao)(bao)裝(zhuang)(zhuang)或排氣(qi)(qi)包(bao)(bao)(bao)裝(zhuang)(zhuang)。