真(zhen)空(kong)(kong)(kong)(kong)，這一(yi)(yi)術(shu)語譯(yi)自拉丁文(wen)vacuo，其意義是(shi)虛無(wu)。其實真(zhen)空(kong)(kong)(kong)(kong)應(ying)理解為(wei)氣體較(jiao)稀薄的(de)空(kong)(kong)(kong)(kong)間。在(zai)指定的(de)空(kong)(kong)(kong)(kong)間內，低于(yu)一(yi)(yi)個大氣壓力(li)的(de)氣體狀態統(tong)稱為(wei)真(zhen)空(kong)(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)(kong)狀態下氣體稀薄程度稱為(wei)真(zhen)空(kong)(kong)(kong)(kong)度（degreeofvacuum），通常用壓力(li)值表示。因此(ci)真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)實際(ji)上不(bu)是(shi)完全真(zhen)空(kong)(kong)(kong)(kong)的(de)，采用真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)技術(shu)包(bao)(bao)裝(zhuang)(zhuang)的(de)食品容器內的(de)真(zhen)空(kong)(kong)(kong)(kong)度通常在(zai)600-1333Pa。所以(yi)，又將(jiang)真(zhen)空(kong)(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)稱為(wei)減(jian)壓包(bao)(bao)裝(zhuang)(zhuang)或排氣包(bao)(bao)裝(zhuang)(zhuang)。