真(zhen)空(kong)(kong)(kong)，這(zhe)一術語譯自拉(la)丁文vacuo，其(qi)意義是(shi)虛無。其(qi)實真(zhen)空(kong)(kong)(kong)應理解為(wei)氣(qi)體較稀(xi)薄的空(kong)(kong)(kong)間(jian)。在指定的空(kong)(kong)(kong)間(jian)內(nei)，低于(yu)一個大氣(qi)壓力的氣(qi)體狀(zhuang)態(tai)統稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀(zhuang)態(tai)下氣(qi)體稀(xi)薄程度(du)稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓力值表示。因(yin)此真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝實際上(shang)不是(shi)完全(quan)真(zhen)空(kong)(kong)(kong)的，采(cai)用真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝技術包(bao)(bao)裝的食(shi)品容(rong)器內(nei)的真(zhen)空(kong)(kong)(kong)度(du)通常在600-1333Pa。所以，又(you)將(jiang)真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝稱(cheng)為(wei)減壓包(bao)(bao)裝或排(pai)氣(qi)包(bao)(bao)裝。