真(zhen)空(kong)(kong)(kong)，這一術語譯自拉丁文vacuo，其意義(yi)是虛無。其實(shi)真(zhen)空(kong)(kong)(kong)應(ying)理解為(wei)(wei)氣(qi)(qi)(qi)體較稀(xi)薄的空(kong)(kong)(kong)間。在指定的空(kong)(kong)(kong)間內(nei)，低(di)于一個(ge)大(da)氣(qi)(qi)(qi)壓力(li)的氣(qi)(qi)(qi)體狀(zhuang)態(tai)統(tong)稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀(zhuang)態(tai)下氣(qi)(qi)(qi)體稀(xi)薄程度稱為(wei)(wei)真(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通常用壓力(li)值表(biao)示(shi)。因此真(zhen)空(kong)(kong)(kong)包裝(zhuang)(zhuang)實(shi)際(ji)上不是完全真(zhen)空(kong)(kong)(kong)的，采用真(zhen)空(kong)(kong)(kong)包裝(zhuang)(zhuang)技術包裝(zhuang)(zhuang)的食品容器內(nei)的真(zhen)空(kong)(kong)(kong)度通常在600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)包裝(zhuang)(zhuang)稱為(wei)(wei)減(jian)壓包裝(zhuang)(zhuang)或排氣(qi)(qi)(qi)包裝(zhuang)(zhuang)。