真(zhen)(zhen)空(kong)(kong)(kong)，這一(yi)術語譯(yi)自拉丁文vacuo，其(qi)意義(yi)是虛(xu)無。其(qi)實真(zhen)(zhen)空(kong)(kong)(kong)應理解(jie)為氣體較稀(xi)薄的空(kong)(kong)(kong)間。在指定的空(kong)(kong)(kong)間內，低(di)于一(yi)個大氣壓力(li)的氣體狀(zhuang)態(tai)統稱(cheng)為真(zhen)(zhen)空(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)狀(zhuang)態(tai)下氣體稀(xi)薄程度(du)稱(cheng)為真(zhen)(zhen)空(kong)(kong)(kong)度(du)（degreeofvacuum），通常用壓力(li)值表示(shi)。因此(ci)真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)實際(ji)上不是完全真(zhen)(zhen)空(kong)(kong)(kong)的，采用真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)技術包(bao)裝(zhuang)的食(shi)品(pin)容器內的真(zhen)(zhen)空(kong)(kong)(kong)度(du)通常在600-1333Pa。所以，又將真(zhen)(zhen)空(kong)(kong)(kong)包(bao)裝(zhuang)稱(cheng)為減壓包(bao)裝(zhuang)或(huo)排氣包(bao)裝(zhuang)。