真(zhen)(zhen)空(kong)(kong)(kong)(kong)，這一術語譯(yi)自拉丁文vacuo，其(qi)意義是虛無。其(qi)實真(zhen)(zhen)空(kong)(kong)(kong)(kong)應理解為氣(qi)體(ti)較稀薄(bo)的(de)空(kong)(kong)(kong)(kong)間。在指(zhi)定的(de)空(kong)(kong)(kong)(kong)間內(nei)，低于一個(ge)大氣(qi)壓(ya)力的(de)氣(qi)體(ti)狀(zhuang)態(tai)統(tong)稱為真(zhen)(zhen)空(kong)(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)(kong)狀(zhuang)態(tai)下氣(qi)體(ti)稀薄(bo)程(cheng)度稱為真(zhen)(zhen)空(kong)(kong)(kong)(kong)度（degreeofvacuum），通常用壓(ya)力值表示。因此真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)實際上不是完全真(zhen)(zhen)空(kong)(kong)(kong)(kong)的(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)技術包(bao)(bao)裝(zhuang)(zhuang)的(de)食品容器內(nei)的(de)真(zhen)(zhen)空(kong)(kong)(kong)(kong)度通常在600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)稱為減(jian)壓(ya)包(bao)(bao)裝(zhuang)(zhuang)或排氣(qi)包(bao)(bao)裝(zhuang)(zhuang)。