真(zhen)(zhen)空(kong)(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其(qi)(qi)意義(yi)是(shi)虛無。其(qi)(qi)實真(zhen)(zhen)空(kong)(kong)(kong)(kong)應(ying)理解為(wei)氣(qi)(qi)體較稀(xi)薄(bo)的空(kong)(kong)(kong)(kong)間(jian)。在指定的空(kong)(kong)(kong)(kong)間(jian)內，低(di)于一個大(da)氣(qi)(qi)壓力的氣(qi)(qi)體狀(zhuang)態統稱(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)(kong)狀(zhuang)態下氣(qi)(qi)體稀(xi)薄(bo)程度稱(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)度（degreeofvacuum），通常用壓力值表示。因此真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)實際上不是(shi)完全真(zhen)(zhen)空(kong)(kong)(kong)(kong)的，采用真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)技術包(bao)裝(zhuang)的食品容(rong)器(qi)內的真(zhen)(zhen)空(kong)(kong)(kong)(kong)度通常在600-1333Pa。所以(yi)，又將(jiang)真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)為(wei)減壓包(bao)裝(zhuang)或排氣(qi)(qi)包(bao)裝(zhuang)。