真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)，這一(yi)術語譯自拉丁文(wen)vacuo，其(qi)意義(yi)是(shi)虛(xu)無。其(qi)實(shi)(shi)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)應理解為(wei)氣(qi)體(ti)(ti)較(jiao)稀(xi)薄(bo)的(de)空(kong)(kong)(kong)間。在(zai)指(zhi)定的(de)空(kong)(kong)(kong)間內，低(di)于一(yi)個大氣(qi)壓力(li)的(de)氣(qi)體(ti)(ti)狀態(tai)統稱(cheng)為(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)狀態(tai)下氣(qi)體(ti)(ti)稀(xi)薄(bo)程度(du)稱(cheng)為(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常用(yong)壓力(li)值表示。因此真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實(shi)(shi)際(ji)上(shang)不是(shi)完全真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)的(de)，采用(yong)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技術包(bao)裝(zhuang)的(de)食品(pin)容器內的(de)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)通(tong)常在(zai)600-1333Pa。所以，又將真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)為(wei)減壓包(bao)裝(zhuang)或排氣(qi)包(bao)裝(zhuang)。