真(zhen)空(kong)(kong)，這一術語譯自(zi)拉丁文vacuo，其意(yi)義是(shi)虛無。其實真(zhen)空(kong)(kong)應理(li)解為氣體較稀(xi)薄(bo)的空(kong)(kong)間。在指(zhi)定(ding)的空(kong)(kong)間內(nei)，低于(yu)一個大氣壓(ya)力的氣體狀態統稱為真(zhen)空(kong)(kong)。真(zhen)空(kong)(kong)狀態下氣體稀(xi)薄(bo)程度(du)稱為真(zhen)空(kong)(kong)度(du)（degreeofvacuum），通常用壓(ya)力值(zhi)表示。因此真(zhen)空(kong)(kong)包(bao)裝(zhuang)(zhuang)實際上不(bu)是(shi)完(wan)全真(zhen)空(kong)(kong)的，采用真(zhen)空(kong)(kong)包(bao)裝(zhuang)(zhuang)技術包(bao)裝(zhuang)(zhuang)的食品(pin)容器內(nei)的真(zhen)空(kong)(kong)度(du)通常在600-1333Pa。所以，又(you)將真(zhen)空(kong)(kong)包(bao)裝(zhuang)(zhuang)稱為減壓(ya)包(bao)裝(zhuang)(zhuang)或排氣包(bao)裝(zhuang)(zhuang)。