真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)，這(zhe)一(yi)術語譯自拉丁文vacuo，其意義是虛無。其實真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)應(ying)理解為(wei)氣(qi)體(ti)較(jiao)稀(xi)薄(bo)的(de)空(kong)(kong)(kong)(kong)間。在(zai)指定的(de)空(kong)(kong)(kong)(kong)間內，低于一(yi)個(ge)大(da)氣(qi)壓(ya)力(li)的(de)氣(qi)體(ti)狀態統稱為(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)。真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)狀態下氣(qi)體(ti)稀(xi)薄(bo)程度(du)稱為(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通常用(yong)壓(ya)力(li)值表示(shi)。因此真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝實際上不是完(wan)全真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)的(de)，采(cai)用(yong)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝技術包(bao)裝的(de)食品容器內的(de)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)度(du)通常在(zai)600-1333Pa。所以，又(you)將真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝稱為(wei)減(jian)壓(ya)包(bao)裝或(huo)排氣(qi)包(bao)裝。