真(zhen)空(kong)(kong)(kong)(kong)，這一(yi)術語譯(yi)自拉丁文vacuo，其意義是虛無。其實(shi)真(zhen)空(kong)(kong)(kong)(kong)應(ying)理解為氣體較稀(xi)薄(bo)的(de)空(kong)(kong)(kong)(kong)間。在(zai)指定的(de)空(kong)(kong)(kong)(kong)間內，低于一(yi)個(ge)大氣壓力的(de)氣體狀(zhuang)態(tai)統稱(cheng)為真(zhen)空(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)狀(zhuang)態(tai)下氣體稀(xi)薄(bo)程度稱(cheng)為真(zhen)空(kong)(kong)(kong)(kong)度（degreeofvacuum），通(tong)常用壓力值表(biao)示。因此真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝實(shi)際上(shang)不是完全真(zhen)空(kong)(kong)(kong)(kong)的(de)，采用真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝技術包(bao)裝的(de)食品容器內的(de)真(zhen)空(kong)(kong)(kong)(kong)度通(tong)常在(zai)600-1333Pa。所(suo)以，又將真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝稱(cheng)為減壓包(bao)裝或排氣包(bao)裝。