真(zhen)(zhen)空(kong)(kong)(kong)，這(zhe)一術(shu)語譯自(zi)拉丁文vacuo，其意義是虛無。其實真(zhen)(zhen)空(kong)(kong)(kong)應理解為(wei)氣(qi)體較稀薄(bo)的(de)空(kong)(kong)(kong)間。在指定的(de)空(kong)(kong)(kong)間內，低于一個大氣(qi)壓力的(de)氣(qi)體狀態(tai)統稱為(wei)真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀態(tai)下氣(qi)體稀薄(bo)程度稱為(wei)真(zhen)(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通(tong)常用壓力值(zhi)表示。因此真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實際上不是完(wan)全真(zhen)(zhen)空(kong)(kong)(kong)的(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技術(shu)包(bao)裝(zhuang)的(de)食品容器(qi)內的(de)真(zhen)(zhen)空(kong)(kong)(kong)度通(tong)常在600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱為(wei)減壓包(bao)裝(zhuang)或(huo)排氣(qi)包(bao)裝(zhuang)。