真(zhen)(zhen)(zhen)空(kong)(kong)(kong)，這一術語譯自(zi)拉丁文(wen)vacuo，其意義是(shi)虛無。其實真(zhen)(zhen)(zhen)空(kong)(kong)(kong)應理解為(wei)(wei)氣體較稀(xi)薄的(de)空(kong)(kong)(kong)間。在指定(ding)的(de)空(kong)(kong)(kong)間內，低(di)于一個(ge)大氣壓力(li)(li)的(de)氣體狀態統稱(cheng)為(wei)(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)狀態下氣體稀(xi)薄程度(du)稱(cheng)為(wei)(wei)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓力(li)(li)值表示。因此真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實際上不是(shi)完全真(zhen)(zhen)(zhen)空(kong)(kong)(kong)的(de)，采用真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技(ji)術包(bao)裝(zhuang)的(de)食(shi)品容器內的(de)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)通常在600-1333Pa。所以，又將真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)為(wei)(wei)減壓包(bao)裝(zhuang)或排氣包(bao)裝(zhuang)。