真(zhen)(zhen)(zhen)空(kong)(kong)，這一術語譯自拉丁文(wen)vacuo，其意義是(shi)虛無(wu)。其實真(zhen)(zhen)(zhen)空(kong)(kong)應理解為氣(qi)(qi)體較稀薄(bo)的空(kong)(kong)間(jian)。在指定的空(kong)(kong)間(jian)內，低于一個大氣(qi)(qi)壓力的氣(qi)(qi)體狀(zhuang)態(tai)統稱(cheng)(cheng)(cheng)為真(zhen)(zhen)(zhen)空(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)狀(zhuang)態(tai)下(xia)氣(qi)(qi)體稀薄(bo)程度稱(cheng)(cheng)(cheng)為真(zhen)(zhen)(zhen)空(kong)(kong)度（degreeofvacuum），通常用壓力值(zhi)表示。因(yin)此(ci)真(zhen)(zhen)(zhen)空(kong)(kong)包裝(zhuang)實際上不是(shi)完(wan)全真(zhen)(zhen)(zhen)空(kong)(kong)的，采(cai)用真(zhen)(zhen)(zhen)空(kong)(kong)包裝(zhuang)技術包裝(zhuang)的食品(pin)容器內的真(zhen)(zhen)(zhen)空(kong)(kong)度通常在600-1333Pa。所以，又將真(zhen)(zhen)(zhen)空(kong)(kong)包裝(zhuang)稱(cheng)(cheng)(cheng)為減壓包裝(zhuang)或排氣(qi)(qi)包裝(zhuang)。