真空(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其意義(yi)是虛無。其實(shi)真空(kong)(kong)(kong)應(ying)理解(jie)為(wei)氣體較稀(xi)薄的空(kong)(kong)(kong)間(jian)。在(zai)指定的空(kong)(kong)(kong)間(jian)內(nei)，低于一個大(da)氣壓(ya)力(li)的氣體狀態(tai)統稱為(wei)真空(kong)(kong)(kong)。真空(kong)(kong)(kong)狀態(tai)下氣體稀(xi)薄程度稱為(wei)真空(kong)(kong)(kong)度（degreeofvacuum），通常用(yong)壓(ya)力(li)值表(biao)示(shi)。因此真空(kong)(kong)(kong)包(bao)裝實(shi)際上不是完全真空(kong)(kong)(kong)的，采用(yong)真空(kong)(kong)(kong)包(bao)裝技術包(bao)裝的食品容器(qi)內(nei)的真空(kong)(kong)(kong)度通常在(zai)600-1333Pa。所以，又將真空(kong)(kong)(kong)包(bao)裝稱為(wei)減(jian)壓(ya)包(bao)裝或排(pai)氣包(bao)裝。