真空(kong)(kong)(kong)，這(zhe)一(yi)術(shu)(shu)語(yu)譯自拉丁文vacuo，其意(yi)義是(shi)虛無。其實真空(kong)(kong)(kong)應理解為氣(qi)(qi)體較稀薄(bo)的(de)(de)空(kong)(kong)(kong)間。在(zai)指定的(de)(de)空(kong)(kong)(kong)間內，低(di)于一(yi)個大氣(qi)(qi)壓力的(de)(de)氣(qi)(qi)體狀態(tai)統稱為真空(kong)(kong)(kong)。真空(kong)(kong)(kong)狀態(tai)下氣(qi)(qi)體稀薄(bo)程度(du)稱為真空(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常用壓力值表示。因(yin)此真空(kong)(kong)(kong)包裝實際上不是(shi)完全真空(kong)(kong)(kong)的(de)(de)，采(cai)用真空(kong)(kong)(kong)包裝技術(shu)(shu)包裝的(de)(de)食品(pin)容器內的(de)(de)真空(kong)(kong)(kong)度(du)通(tong)常在(zai)600-1333Pa。所以，又將真空(kong)(kong)(kong)包裝稱為減壓包裝或(huo)排氣(qi)(qi)包裝。