真(zhen)(zhen)(zhen)空(kong)(kong)(kong)，這一(yi)術語譯自(zi)拉丁文(wen)vacuo，其意義是(shi)虛無。其實真(zhen)(zhen)(zhen)空(kong)(kong)(kong)應理解為(wei)氣(qi)(qi)體(ti)較稀薄(bo)的空(kong)(kong)(kong)間(jian)。在指定的空(kong)(kong)(kong)間(jian)內(nei)，低于一(yi)個大氣(qi)(qi)壓力(li)的氣(qi)(qi)體(ti)狀(zhuang)態(tai)統稱(cheng)為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)狀(zhuang)態(tai)下氣(qi)(qi)體(ti)稀薄(bo)程度(du)稱(cheng)為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓力(li)值表示。因(yin)此(ci)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包裝實際上(shang)不是(shi)完全真(zhen)(zhen)(zhen)空(kong)(kong)(kong)的，采用真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包裝技術包裝的食品容器內(nei)的真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)通常在600-1333Pa。所以(yi)，又將真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包裝稱(cheng)為(wei)減壓包裝或排氣(qi)(qi)包裝。