真(zhen)空(kong)(kong)(kong)，這(zhe)一術語譯(yi)自(zi)拉丁(ding)文vacuo，其意(yi)義是虛無。其實真(zhen)空(kong)(kong)(kong)應(ying)理解為氣體(ti)較稀薄的空(kong)(kong)(kong)間。在(zai)指定的空(kong)(kong)(kong)間內，低于一個大氣壓力(li)(li)的氣體(ti)狀態統稱為真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀態下氣體(ti)稀薄程度(du)稱為真(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常(chang)用(yong)壓力(li)(li)值表示。因此真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)實際上不是完全真(zhen)空(kong)(kong)(kong)的，采(cai)用(yong)真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)技(ji)術包(bao)(bao)裝(zhuang)(zhuang)的食(shi)品容(rong)器內的真(zhen)空(kong)(kong)(kong)度(du)通(tong)常(chang)在(zai)600-1333Pa。所以，又將真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)稱為減壓包(bao)(bao)裝(zhuang)(zhuang)或排氣包(bao)(bao)裝(zhuang)(zhuang)。