真(zhen)空(kong)(kong)(kong)，這一術語(yu)譯自(zi)拉丁文vacuo，其意義是(shi)虛無。其實真(zhen)空(kong)(kong)(kong)應理解為(wei)氣(qi)(qi)體(ti)(ti)較(jiao)稀薄的空(kong)(kong)(kong)間。在指定的空(kong)(kong)(kong)間內，低于一個大氣(qi)(qi)壓(ya)力的氣(qi)(qi)體(ti)(ti)狀態統稱(cheng)(cheng)為(wei)真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀態下(xia)氣(qi)(qi)體(ti)(ti)稀薄程(cheng)度稱(cheng)(cheng)為(wei)真(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通(tong)常(chang)用(yong)(yong)壓(ya)力值(zhi)表示。因(yin)此真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實際上不是(shi)完全真(zhen)空(kong)(kong)(kong)的，采用(yong)(yong)真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技(ji)術包(bao)裝(zhuang)的食品容(rong)器內的真(zhen)空(kong)(kong)(kong)度通(tong)常(chang)在600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)(cheng)為(wei)減壓(ya)包(bao)裝(zhuang)或(huo)排氣(qi)(qi)包(bao)裝(zhuang)。