真(zhen)空(kong)(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其(qi)意義是虛無。其(qi)實真(zhen)空(kong)(kong)(kong)(kong)應(ying)理解為(wei)氣(qi)體(ti)較(jiao)稀薄的(de)空(kong)(kong)(kong)(kong)間。在指定(ding)的(de)空(kong)(kong)(kong)(kong)間內(nei)，低于一個大氣(qi)壓(ya)力的(de)氣(qi)體(ti)狀(zhuang)態(tai)統稱為(wei)真(zhen)空(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)狀(zhuang)態(tai)下氣(qi)體(ti)稀薄程(cheng)度稱為(wei)真(zhen)空(kong)(kong)(kong)(kong)度（degreeofvacuum），通常用(yong)(yong)壓(ya)力值(zhi)表(biao)示。因(yin)此真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝實際上不是完全真(zhen)空(kong)(kong)(kong)(kong)的(de)，采用(yong)(yong)真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝技術包(bao)裝的(de)食品容器內(nei)的(de)真(zhen)空(kong)(kong)(kong)(kong)度通常在600-1333Pa。所(suo)以，又將真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝稱為(wei)減壓(ya)包(bao)裝或排氣(qi)包(bao)裝。