真(zhen)空(kong)(kong)(kong)，這一術語譯自拉(la)丁文vacuo，其意義是虛無。其實(shi)真(zhen)空(kong)(kong)(kong)應理解(jie)為氣體較(jiao)稀(xi)薄的(de)空(kong)(kong)(kong)間(jian)。在指定(ding)的(de)空(kong)(kong)(kong)間(jian)內(nei)，低(di)于(yu)一個大氣壓(ya)力(li)的(de)氣體狀(zhuang)態統稱(cheng)為真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀(zhuang)態下氣體稀(xi)薄程度稱(cheng)為真(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通常用(yong)壓(ya)力(li)值表(biao)示。因此真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)實(shi)際(ji)上(shang)不是完全真(zhen)空(kong)(kong)(kong)的(de)，采用(yong)真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)技術包(bao)裝(zhuang)(zhuang)的(de)食品容器內(nei)的(de)真(zhen)空(kong)(kong)(kong)度通常在600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)稱(cheng)為減壓(ya)包(bao)裝(zhuang)(zhuang)或排氣包(bao)裝(zhuang)(zhuang)。