真(zhen)(zhen)空(kong)(kong)(kong)，這一(yi)術語譯自拉(la)丁(ding)文vacuo，其意(yi)義是(shi)虛(xu)無(wu)。其實(shi)真(zhen)(zhen)空(kong)(kong)(kong)應理解為(wei)(wei)氣(qi)體(ti)較稀薄的(de)空(kong)(kong)(kong)間。在指定的(de)空(kong)(kong)(kong)間內，低于一(yi)個大(da)氣(qi)壓力(li)的(de)氣(qi)體(ti)狀態(tai)統(tong)稱(cheng)(cheng)為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀態(tai)下氣(qi)體(ti)稀薄程(cheng)度稱(cheng)(cheng)為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通(tong)常用壓力(li)值表示。因此(ci)真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)實(shi)際上不(bu)是(shi)完(wan)全真(zhen)(zhen)空(kong)(kong)(kong)的(de)，采(cai)用真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)技術包(bao)裝(zhuang)(zhuang)的(de)食品容器內的(de)真(zhen)(zhen)空(kong)(kong)(kong)度通(tong)常在600-1333Pa。所以，又將(jiang)真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)稱(cheng)(cheng)為(wei)(wei)減壓包(bao)裝(zhuang)(zhuang)或排氣(qi)包(bao)裝(zhuang)(zhuang)。