真(zhen)(zhen)空(kong)(kong)，這一術(shu)語譯自(zi)拉丁文vacuo，其(qi)意(yi)義是虛無。其(qi)實真(zhen)(zhen)空(kong)(kong)應理解為(wei)氣(qi)體較稀薄的(de)空(kong)(kong)間。在指定的(de)空(kong)(kong)間內(nei)(nei)，低于一個大(da)氣(qi)壓(ya)力(li)的(de)氣(qi)體狀態(tai)統稱為(wei)真(zhen)(zhen)空(kong)(kong)。真(zhen)(zhen)空(kong)(kong)狀態(tai)下氣(qi)體稀薄程度(du)(du)稱為(wei)真(zhen)(zhen)空(kong)(kong)度(du)(du)（degreeofvacuum），通(tong)常(chang)用(yong)(yong)壓(ya)力(li)值表示。因(yin)此真(zhen)(zhen)空(kong)(kong)包(bao)(bao)裝(zhuang)實際上不是完全真(zhen)(zhen)空(kong)(kong)的(de)，采用(yong)(yong)真(zhen)(zhen)空(kong)(kong)包(bao)(bao)裝(zhuang)技術(shu)包(bao)(bao)裝(zhuang)的(de)食品容器內(nei)(nei)的(de)真(zhen)(zhen)空(kong)(kong)度(du)(du)通(tong)常(chang)在600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)包(bao)(bao)裝(zhuang)稱為(wei)減壓(ya)包(bao)(bao)裝(zhuang)或排(pai)氣(qi)包(bao)(bao)裝(zhuang)。