真(zhen)(zhen)空(kong)(kong)(kong)，這一(yi)術語譯自拉丁文vacuo，其(qi)意義是虛無(wu)。其(qi)實真(zhen)(zhen)空(kong)(kong)(kong)應理解為氣(qi)(qi)體(ti)較(jiao)稀薄的(de)(de)空(kong)(kong)(kong)間。在指定的(de)(de)空(kong)(kong)(kong)間內(nei)，低于一(yi)個(ge)大氣(qi)(qi)壓(ya)力的(de)(de)氣(qi)(qi)體(ti)狀態統稱(cheng)(cheng)為真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀態下氣(qi)(qi)體(ti)稀薄程(cheng)度(du)(du)稱(cheng)(cheng)為真(zhen)(zhen)空(kong)(kong)(kong)度(du)(du)（degreeofvacuum），通(tong)常用壓(ya)力值表示。因此(ci)真(zhen)(zhen)空(kong)(kong)(kong)包(bao)(bao)裝實際(ji)上不是完(wan)全真(zhen)(zhen)空(kong)(kong)(kong)的(de)(de)，采用真(zhen)(zhen)空(kong)(kong)(kong)包(bao)(bao)裝技術包(bao)(bao)裝的(de)(de)食品(pin)容(rong)器內(nei)的(de)(de)真(zhen)(zhen)空(kong)(kong)(kong)度(du)(du)通(tong)常在600-1333Pa。所以(yi)，又將真(zhen)(zhen)空(kong)(kong)(kong)包(bao)(bao)裝稱(cheng)(cheng)為減壓(ya)包(bao)(bao)裝或(huo)排氣(qi)(qi)包(bao)(bao)裝。