真(zhen)空(kong)(kong)(kong)，這一(yi)術(shu)語譯自拉(la)丁文vacuo，其意義是(shi)虛無。其實真(zhen)空(kong)(kong)(kong)應理(li)解為(wei)氣(qi)體(ti)(ti)較稀薄的(de)空(kong)(kong)(kong)間。在指(zhi)定的(de)空(kong)(kong)(kong)間內(nei)，低(di)于(yu)一(yi)個(ge)大(da)氣(qi)壓力的(de)氣(qi)體(ti)(ti)狀態(tai)統稱為(wei)真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀態(tai)下氣(qi)體(ti)(ti)稀薄程(cheng)度(du)稱為(wei)真(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓力值表示。因此真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)(zhuang)實際上不是(shi)完全真(zhen)空(kong)(kong)(kong)的(de)，采用真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)(zhuang)技術(shu)包(bao)裝(zhuang)(zhuang)(zhuang)的(de)食品容(rong)器內(nei)的(de)真(zhen)空(kong)(kong)(kong)度(du)通常在600-1333Pa。所以(yi)，又將真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)(zhuang)(zhuang)稱為(wei)減(jian)壓包(bao)裝(zhuang)(zhuang)(zhuang)或排氣(qi)包(bao)裝(zhuang)(zhuang)(zhuang)。