真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其意義是虛無。其實真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)應理解為(wei)氣(qi)(qi)體(ti)較稀薄(bo)的(de)(de)空(kong)(kong)(kong)(kong)間。在指定的(de)(de)空(kong)(kong)(kong)(kong)間內(nei)，低于一個大氣(qi)(qi)壓力(li)的(de)(de)氣(qi)(qi)體(ti)狀態統稱為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)狀態下氣(qi)(qi)體(ti)稀薄(bo)程度(du)稱為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓力(li)值表示。因(yin)此(ci)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)實際上不是完全(quan)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)的(de)(de)，采用真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)技術包裝(zhuang)的(de)(de)食品(pin)容器內(nei)的(de)(de)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)度(du)通常在600-1333Pa。所(suo)以(yi)，又將真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)稱為(wei)減壓包裝(zhuang)或排氣(qi)(qi)包裝(zhuang)。