真(zhen)空(kong)(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其意義是虛無。其實真(zhen)空(kong)(kong)(kong)(kong)應理解為氣體(ti)較稀(xi)(xi)薄的(de)空(kong)(kong)(kong)(kong)間。在(zai)指定(ding)的(de)空(kong)(kong)(kong)(kong)間內，低(di)于(yu)一個大氣壓力的(de)氣體(ti)狀(zhuang)態統稱(cheng)為真(zhen)空(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)狀(zhuang)態下氣體(ti)稀(xi)(xi)薄程度(du)稱(cheng)為真(zhen)空(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通常(chang)用壓力值表示。因此真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)實際上不(bu)是完全真(zhen)空(kong)(kong)(kong)(kong)的(de)，采用真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)技術包(bao)(bao)裝(zhuang)(zhuang)的(de)食品容器內的(de)真(zhen)空(kong)(kong)(kong)(kong)度(du)通常(chang)在(zai)600-1333Pa。所以，又(you)將(jiang)真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)稱(cheng)為減(jian)壓包(bao)(bao)裝(zhuang)(zhuang)或排氣包(bao)(bao)裝(zhuang)(zhuang)。