真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)，這一(yi)術語譯(yi)自拉丁文(wen)vacuo，其意義(yi)是虛無。其實(shi)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)應理解(jie)為(wei)氣體較稀薄的(de)(de)空(kong)(kong)(kong)(kong)(kong)間。在指定的(de)(de)空(kong)(kong)(kong)(kong)(kong)間內，低(di)于(yu)一(yi)個大(da)氣壓(ya)力的(de)(de)氣體狀(zhuang)態統稱(cheng)為(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)。真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)狀(zhuang)態下氣體稀薄程(cheng)度(du)稱(cheng)為(wei)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常用壓(ya)力值表(biao)示。因此真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)實(shi)際上不是完(wan)全(quan)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)的(de)(de)，采用真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)技術包裝(zhuang)的(de)(de)食(shi)品容器(qi)內的(de)(de)真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)度(du)通(tong)常在600-1333Pa。所以(yi)，又將真(zhen)(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)包裝(zhuang)稱(cheng)為(wei)減壓(ya)包裝(zhuang)或(huo)排氣包裝(zhuang)。