真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)，這一術語譯自拉丁(ding)文vacuo，其意義(yi)是虛無(wu)。其實真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)應理解為(wei)氣(qi)(qi)體(ti)(ti)較稀(xi)薄的空(kong)(kong)(kong)(kong)(kong)(kong)間。在(zai)指定(ding)的空(kong)(kong)(kong)(kong)(kong)(kong)間內(nei)(nei)，低于一個(ge)大氣(qi)(qi)壓(ya)(ya)力的氣(qi)(qi)體(ti)(ti)狀態統稱為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)狀態下氣(qi)(qi)體(ti)(ti)稀(xi)薄程(cheng)度(du)(du)(du)稱為(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)度(du)(du)(du)（degreeofvacuum），通(tong)常(chang)用壓(ya)(ya)力值表示。因(yin)此(ci)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)包裝實際上(shang)不是完(wan)全(quan)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)的，采用真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)包裝技(ji)術包裝的食(shi)品容器內(nei)(nei)的真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)度(du)(du)(du)通(tong)常(chang)在(zai)600-1333Pa。所以，又將真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)包裝稱為(wei)減壓(ya)(ya)包裝或排氣(qi)(qi)包裝。