真(zhen)(zhen)(zhen)空(kong)(kong)(kong)，這一術語譯(yi)自拉丁文vacuo，其意義是虛(xu)無。其實真(zhen)(zhen)(zhen)空(kong)(kong)(kong)應理解為氣體(ti)(ti)(ti)較稀(xi)薄的空(kong)(kong)(kong)間(jian)。在指定的空(kong)(kong)(kong)間(jian)內，低于一個大氣壓(ya)力(li)的氣體(ti)(ti)(ti)狀(zhuang)態統(tong)稱為真(zhen)(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)狀(zhuang)態下(xia)氣體(ti)(ti)(ti)稀(xi)薄程度稱為真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通常用(yong)壓(ya)力(li)值表示(shi)。因此真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝實際上(shang)不是完(wan)全(quan)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)的，采(cai)用(yong)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝技術包(bao)裝的食品容器內的真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度通常在600-1333Pa。所以，又將真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝稱為減壓(ya)包(bao)裝或排(pai)氣包(bao)裝。