真(zhen)空(kong)(kong)，這一(yi)術語譯自拉丁(ding)文vacuo，其意義是虛無。其實真(zhen)空(kong)(kong)應理解為(wei)(wei)氣(qi)(qi)體較(jiao)稀薄(bo)的(de)(de)空(kong)(kong)間。在指(zhi)定的(de)(de)空(kong)(kong)間內，低(di)于一(yi)個(ge)大(da)氣(qi)(qi)壓(ya)力的(de)(de)氣(qi)(qi)體狀態統稱(cheng)(cheng)為(wei)(wei)真(zhen)空(kong)(kong)。真(zhen)空(kong)(kong)狀態下氣(qi)(qi)體稀薄(bo)程度稱(cheng)(cheng)為(wei)(wei)真(zhen)空(kong)(kong)度（degreeofvacuum），通(tong)常用(yong)壓(ya)力值表示。因此真(zhen)空(kong)(kong)包(bao)(bao)裝實際上不(bu)是完(wan)全真(zhen)空(kong)(kong)的(de)(de)，采用(yong)真(zhen)空(kong)(kong)包(bao)(bao)裝技術包(bao)(bao)裝的(de)(de)食品容(rong)器內的(de)(de)真(zhen)空(kong)(kong)度通(tong)常在600-1333Pa。所以，又(you)將真(zhen)空(kong)(kong)包(bao)(bao)裝稱(cheng)(cheng)為(wei)(wei)減壓(ya)包(bao)(bao)裝或排氣(qi)(qi)包(bao)(bao)裝。