真(zhen)(zhen)空(kong)(kong)(kong)，這一術(shu)語譯自拉丁文vacuo，其意義是虛無(wu)。其實真(zhen)(zhen)空(kong)(kong)(kong)應理(li)解為(wei)(wei)氣(qi)(qi)體較稀(xi)薄的(de)(de)空(kong)(kong)(kong)間。在(zai)指定(ding)的(de)(de)空(kong)(kong)(kong)間內，低于一個(ge)大氣(qi)(qi)壓力的(de)(de)氣(qi)(qi)體狀態統稱為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀態下氣(qi)(qi)體稀(xi)薄程(cheng)度稱為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通(tong)常用壓力值(zhi)表(biao)示。因此真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝實際(ji)上(shang)不是完全真(zhen)(zhen)空(kong)(kong)(kong)的(de)(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝技術(shu)包(bao)裝的(de)(de)食品容器內的(de)(de)真(zhen)(zhen)空(kong)(kong)(kong)度通(tong)常在(zai)600-1333Pa。所以，又將(jiang)真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝稱為(wei)(wei)減壓包(bao)裝或排(pai)氣(qi)(qi)包(bao)裝。