真(zhen)(zhen)(zhen)空(kong)(kong)(kong)，這一術語(yu)譯(yi)自(zi)拉丁文vacuo，其意義是虛無。其實(shi)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)應(ying)理(li)解為氣體(ti)較稀(xi)(xi)薄的(de)(de)空(kong)(kong)(kong)間。在(zai)指定的(de)(de)空(kong)(kong)(kong)間內，低于(yu)一個大氣壓(ya)(ya)力的(de)(de)氣體(ti)狀態統稱(cheng)為真(zhen)(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)狀態下(xia)氣體(ti)稀(xi)(xi)薄程度(du)稱(cheng)為真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常(chang)用壓(ya)(ya)力值(zhi)表示。因此(ci)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)(bao)裝實(shi)際(ji)上不是完全真(zhen)(zhen)(zhen)空(kong)(kong)(kong)的(de)(de)，采用真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)(bao)裝技術包(bao)(bao)裝的(de)(de)食品容器內的(de)(de)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)度(du)通常(chang)在(zai)600-1333Pa。所以，又將真(zhen)(zhen)(zhen)空(kong)(kong)(kong)包(bao)(bao)裝稱(cheng)為減壓(ya)(ya)包(bao)(bao)裝或排氣包(bao)(bao)裝。