真(zhen)(zhen)空(kong)(kong)(kong)，這(zhe)一術語譯自拉丁文vacuo，其意(yi)義(yi)是虛無。其實真(zhen)(zhen)空(kong)(kong)(kong)應理(li)解為(wei)氣體(ti)較稀(xi)薄的(de)(de)空(kong)(kong)(kong)間。在指定的(de)(de)空(kong)(kong)(kong)間內(nei)，低(di)于一個大(da)氣壓力的(de)(de)氣體(ti)狀態(tai)(tai)統稱(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀態(tai)(tai)下氣體(ti)稀(xi)薄程度(du)稱(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常(chang)用(yong)壓力值(zhi)表示。因(yin)此真(zhen)(zhen)空(kong)(kong)(kong)包裝實際上不是完(wan)全真(zhen)(zhen)空(kong)(kong)(kong)的(de)(de)，采用(yong)真(zhen)(zhen)空(kong)(kong)(kong)包裝技術包裝的(de)(de)食(shi)品(pin)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)包裝稱(cheng)為(wei)減壓包裝或排(pai)氣包裝。