真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)，這(zhe)一術(shu)語譯(yi)自拉丁(ding)文vacuo，其意(yi)義是虛(xu)無。其實(shi)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)應理解為(wei)(wei)氣(qi)(qi)(qi)體(ti)較稀薄的空(kong)(kong)(kong)間。在指定的空(kong)(kong)(kong)間內，低(di)于一個大氣(qi)(qi)(qi)壓(ya)力的氣(qi)(qi)(qi)體(ti)狀態(tai)統稱(cheng)(cheng)為(wei)(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)(qi)(qi)體(ti)稀薄程度(du)稱(cheng)(cheng)為(wei)(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓(ya)力值表示。因此真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實(shi)際上(shang)不是完全真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)的，采(cai)用真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技術(shu)包(bao)裝(zhuang)的食品容器(qi)內的真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)通常在600-1333Pa。所以(yi)，又將真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)(cheng)為(wei)(wei)減壓(ya)包(bao)裝(zhuang)或排氣(qi)(qi)(qi)包(bao)裝(zhuang)。