真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)，這一(yi)術語譯自(zi)拉(la)丁文vacuo，其(qi)(qi)意義是虛無。其(qi)(qi)實真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)應理解為(wei)氣(qi)體(ti)較稀(xi)薄(bo)的(de)空(kong)(kong)(kong)(kong)(kong)間。在(zai)指定的(de)空(kong)(kong)(kong)(kong)(kong)間內，低于一(yi)個大氣(qi)壓(ya)力的(de)氣(qi)體(ti)狀態統稱為(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)狀態下(xia)氣(qi)體(ti)稀(xi)薄(bo)程度稱為(wei)真(zhen)(zhen)空(kong)(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)(kong)包(bao)(bao)裝(zhuang)(zhuang)(zhuang)實際(ji)上不是完全真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)的(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)(zhuang)技術包(bao)(bao)裝(zhuang)(zhuang)(zhuang)的(de)食(shi)品容器內的(de)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)度通常在(zai)600-1333Pa。所以，又將(jiang)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)(zhuang)稱為(wei)減(jian)壓(ya)包(bao)(bao)裝(zhuang)(zhuang)(zhuang)或排氣(qi)包(bao)(bao)裝(zhuang)(zhuang)(zhuang)。