真(zhen)空(kong)(kong)(kong)(kong)，這一術(shu)(shu)語(yu)譯自拉丁文vacuo，其意義是虛無(wu)。其實真(zhen)空(kong)(kong)(kong)(kong)應理(li)解為氣(qi)(qi)體(ti)較稀薄的(de)空(kong)(kong)(kong)(kong)間(jian)。在(zai)(zai)指定的(de)空(kong)(kong)(kong)(kong)間(jian)內，低(di)于(yu)一個(ge)大(da)氣(qi)(qi)壓(ya)力的(de)氣(qi)(qi)體(ti)狀態(tai)(tai)統稱(cheng)為真(zhen)空(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)狀態(tai)(tai)下氣(qi)(qi)體(ti)稀薄程度(du)(du)稱(cheng)為真(zhen)空(kong)(kong)(kong)(kong)度(du)(du)（degreeofvacuum），通常用(yong)壓(ya)力值表示(shi)。因此真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)實際上不是完全真(zhen)空(kong)(kong)(kong)(kong)的(de)，采用(yong)真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)技術(shu)(shu)包(bao)裝(zhuang)的(de)食品容器內的(de)真(zhen)空(kong)(kong)(kong)(kong)度(du)(du)通常在(zai)(zai)600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)為減壓(ya)包(bao)裝(zhuang)或排氣(qi)(qi)包(bao)裝(zhuang)。