真(zhen)(zhen)空(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其意義(yi)是(shi)虛(xu)無。其實真(zhen)(zhen)空(kong)(kong)(kong)應理解為(wei)氣(qi)(qi)體(ti)較稀薄的(de)(de)空(kong)(kong)(kong)間。在指定的(de)(de)空(kong)(kong)(kong)間內(nei)，低于一個大(da)氣(qi)(qi)壓(ya)力的(de)(de)氣(qi)(qi)體(ti)狀(zhuang)態統稱為(wei)真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀(zhuang)態下氣(qi)(qi)體(ti)稀薄程(cheng)度(du)稱為(wei)真(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常(chang)用壓(ya)力值(zhi)表示。因此真(zhen)(zhen)空(kong)(kong)(kong)包裝(zhuang)實際上不是(shi)完全真(zhen)(zhen)空(kong)(kong)(kong)的(de)(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)包裝(zhuang)技術包裝(zhuang)的(de)(de)食品容器內(nei)的(de)(de)真(zhen)(zhen)空(kong)(kong)(kong)度(du)通常(chang)在600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)包裝(zhuang)稱為(wei)減壓(ya)包裝(zhuang)或排氣(qi)(qi)包裝(zhuang)。