真(zhen)空(kong)(kong)，這一(yi)術語(yu)譯自拉丁文vacuo，其意義是(shi)虛無。其實真(zhen)空(kong)(kong)應理(li)解為氣體較稀(xi)薄(bo)的空(kong)(kong)間。在(zai)指定的空(kong)(kong)間內，低于(yu)一(yi)個大氣壓力的氣體狀態(tai)統稱為真(zhen)空(kong)(kong)。真(zhen)空(kong)(kong)狀態(tai)下氣體稀(xi)薄(bo)程(cheng)度(du)稱為真(zhen)空(kong)(kong)度(du)（degreeofvacuum），通(tong)(tong)常(chang)用(yong)壓力值(zhi)表示。因此真(zhen)空(kong)(kong)包裝(zhuang)(zhuang)實際上(shang)不是(shi)完全真(zhen)空(kong)(kong)的，采用(yong)真(zhen)空(kong)(kong)包裝(zhuang)(zhuang)技術包裝(zhuang)(zhuang)的食(shi)品容(rong)器內的真(zhen)空(kong)(kong)度(du)通(tong)(tong)常(chang)在(zai)600-1333Pa。所以，又(you)將真(zhen)空(kong)(kong)包裝(zhuang)(zhuang)稱為減壓包裝(zhuang)(zhuang)或排氣包裝(zhuang)(zhuang)。