真(zhen)空(kong)(kong)(kong)，這一術(shu)語譯自拉(la)丁文vacuo，其意義是虛無(wu)。其實真(zhen)空(kong)(kong)(kong)應理解(jie)為(wei)(wei)氣(qi)體較稀(xi)薄(bo)的(de)空(kong)(kong)(kong)間(jian)。在(zai)指定(ding)的(de)空(kong)(kong)(kong)間(jian)內，低于(yu)一個大氣(qi)壓(ya)(ya)力的(de)氣(qi)體狀態統(tong)稱(cheng)(cheng)為(wei)(wei)真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀態下氣(qi)體稀(xi)薄(bo)程度稱(cheng)(cheng)為(wei)(wei)真(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通常用(yong)壓(ya)(ya)力值表示。因此真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)實際上(shang)不是完(wan)全真(zhen)空(kong)(kong)(kong)的(de)，采用(yong)真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)技(ji)術(shu)包(bao)(bao)裝(zhuang)的(de)食品容器(qi)內的(de)真(zhen)空(kong)(kong)(kong)度通常在(zai)600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)稱(cheng)(cheng)為(wei)(wei)減(jian)壓(ya)(ya)包(bao)(bao)裝(zhuang)或排氣(qi)包(bao)(bao)裝(zhuang)。