真(zhen)空(kong)(kong)，這一術語(yu)譯自拉丁文vacuo，其(qi)意義是虛無。其(qi)實(shi)真(zhen)空(kong)(kong)應理解(jie)為(wei)氣(qi)(qi)(qi)(qi)體較(jiao)稀薄(bo)(bo)的空(kong)(kong)間(jian)。在指定(ding)的空(kong)(kong)間(jian)內，低于一個大氣(qi)(qi)(qi)(qi)壓(ya)力的氣(qi)(qi)(qi)(qi)體狀態統稱為(wei)真(zhen)空(kong)(kong)。真(zhen)空(kong)(kong)狀態下氣(qi)(qi)(qi)(qi)體稀薄(bo)(bo)程度稱為(wei)真(zhen)空(kong)(kong)度（degreeofvacuum），通常用壓(ya)力值表示(shi)。因此真(zhen)空(kong)(kong)包(bao)裝(zhuang)實(shi)際(ji)上不是完全真(zhen)空(kong)(kong)的，采用真(zhen)空(kong)(kong)包(bao)裝(zhuang)技術包(bao)裝(zhuang)的食(shi)品容器(qi)內的真(zhen)空(kong)(kong)度通常在600-1333Pa。所(suo)以(yi)，又(you)將真(zhen)空(kong)(kong)包(bao)裝(zhuang)稱為(wei)減壓(ya)包(bao)裝(zhuang)或排氣(qi)(qi)(qi)(qi)包(bao)裝(zhuang)。