真(zhen)空(kong)(kong)(kong)，這一(yi)術語譯自(zi)拉丁文vacuo，其意義是(shi)虛無。其實真(zhen)空(kong)(kong)(kong)應(ying)理解為氣(qi)體(ti)較(jiao)稀(xi)薄的(de)空(kong)(kong)(kong)間(jian)。在(zai)(zai)指定的(de)空(kong)(kong)(kong)間(jian)內，低于一(yi)個大(da)氣(qi)壓(ya)力的(de)氣(qi)體(ti)狀態統稱為真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀態下(xia)氣(qi)體(ti)稀(xi)薄程(cheng)度(du)稱為真(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓(ya)力值表示。因(yin)此真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實際上不是(shi)完全真(zhen)空(kong)(kong)(kong)的(de)，采用真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技術包(bao)裝(zhuang)的(de)食品(pin)容器內的(de)真(zhen)空(kong)(kong)(kong)度(du)通常在(zai)(zai)600-1333Pa。所(suo)以，又將真(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱為減壓(ya)包(bao)裝(zhuang)或排氣(qi)包(bao)裝(zhuang)。