真(zhen)空(kong)(kong)(kong)(kong)，這一(yi)術(shu)(shu)語譯自拉丁文vacuo，其意義是虛無(wu)。其實真(zhen)空(kong)(kong)(kong)(kong)應理解為(wei)氣(qi)體(ti)(ti)較稀薄(bo)的(de)(de)(de)(de)空(kong)(kong)(kong)(kong)間。在(zai)指定(ding)的(de)(de)(de)(de)空(kong)(kong)(kong)(kong)間內，低于一(yi)個大氣(qi)壓力的(de)(de)(de)(de)氣(qi)體(ti)(ti)狀態(tai)統稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)狀態(tai)下氣(qi)體(ti)(ti)稀薄(bo)程度(du)稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通常(chang)用(yong)壓力值表示。因此(ci)真(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)實際上不是完全真(zhen)空(kong)(kong)(kong)(kong)的(de)(de)(de)(de)，采用(yong)真(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)技術(shu)(shu)包裝(zhuang)的(de)(de)(de)(de)食品容器內的(de)(de)(de)(de)真(zhen)空(kong)(kong)(kong)(kong)度(du)通常(chang)在(zai)600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)(kong)包裝(zhuang)稱(cheng)為(wei)減(jian)壓包裝(zhuang)或排氣(qi)包裝(zhuang)。