真(zhen)空(kong)(kong)(kong)，這一術(shu)語譯自拉丁文vacuo，其(qi)意義(yi)是虛(xu)無。其(qi)實(shi)真(zhen)空(kong)(kong)(kong)應理解為(wei)(wei)氣(qi)體較(jiao)稀薄的(de)(de)空(kong)(kong)(kong)間(jian)(jian)。在指定的(de)(de)空(kong)(kong)(kong)間(jian)(jian)內，低于一個大氣(qi)壓力(li)的(de)(de)氣(qi)體狀態統稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀態下氣(qi)體稀薄程度稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通常(chang)用(yong)壓力(li)值表示。因此真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)實(shi)際上(shang)不是完全(quan)真(zhen)空(kong)(kong)(kong)的(de)(de)，采用(yong)真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)技術(shu)包(bao)(bao)裝(zhuang)的(de)(de)食品容器內的(de)(de)真(zhen)空(kong)(kong)(kong)度通常(chang)在600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)稱為(wei)(wei)減壓包(bao)(bao)裝(zhuang)或排氣(qi)包(bao)(bao)裝(zhuang)。