真(zhen)(zhen)(zhen)空(kong)(kong)，這一術語譯自拉丁(ding)文vacuo，其意義是(shi)虛無。其實真(zhen)(zhen)(zhen)空(kong)(kong)應理(li)解(jie)為(wei)氣(qi)(qi)體較(jiao)稀薄的空(kong)(kong)間(jian)。在指定的空(kong)(kong)間(jian)內，低于(yu)一個大氣(qi)(qi)壓力的氣(qi)(qi)體狀態統稱為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)狀態下氣(qi)(qi)體稀薄程度稱為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)度（degreeofvacuum），通(tong)常(chang)用壓力值表示。因此真(zhen)(zhen)(zhen)空(kong)(kong)包(bao)裝(zhuang)實際(ji)上不(bu)是(shi)完全真(zhen)(zhen)(zhen)空(kong)(kong)的，采用真(zhen)(zhen)(zhen)空(kong)(kong)包(bao)裝(zhuang)技術包(bao)裝(zhuang)的食品容器內的真(zhen)(zhen)(zhen)空(kong)(kong)度通(tong)常(chang)在600-1333Pa。所以，又將真(zhen)(zhen)(zhen)空(kong)(kong)包(bao)裝(zhuang)稱為(wei)減壓包(bao)裝(zhuang)或排(pai)氣(qi)(qi)包(bao)裝(zhuang)。