真(zhen)(zhen)空(kong)(kong)(kong)，這一術(shu)語譯(yi)自拉丁文(wen)vacuo，其意義是(shi)虛(xu)無(wu)。其實真(zhen)(zhen)空(kong)(kong)(kong)應理解(jie)為(wei)氣體較稀(xi)薄(bo)的空(kong)(kong)(kong)間(jian)。在指定的空(kong)(kong)(kong)間(jian)內，低于一個大(da)氣壓(ya)力(li)的氣體狀態統稱(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀態下氣體稀(xi)薄(bo)程度稱(cheng)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通常(chang)用壓(ya)力(li)值表(biao)示。因此真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實際(ji)上不是(shi)完全真(zhen)(zhen)空(kong)(kong)(kong)的，采用真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技術(shu)包(bao)裝(zhuang)的食品容(rong)器內的真(zhen)(zhen)空(kong)(kong)(kong)度通常(chang)在600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)為(wei)減壓(ya)包(bao)裝(zhuang)或排氣包(bao)裝(zhuang)。