真(zhen)(zhen)空(kong)(kong)，這一(yi)術語(yu)譯自(zi)拉丁文vacuo，其(qi)意義是虛無(wu)。其(qi)實(shi)真(zhen)(zhen)空(kong)(kong)應理解為氣(qi)體較稀薄(bo)的空(kong)(kong)間。在(zai)指定的空(kong)(kong)間內，低于(yu)一(yi)個大(da)氣(qi)壓(ya)力的氣(qi)體狀態統(tong)稱(cheng)為真(zhen)(zhen)空(kong)(kong)。真(zhen)(zhen)空(kong)(kong)狀態下氣(qi)體稀薄(bo)程度稱(cheng)為真(zhen)(zhen)空(kong)(kong)度（degreeofvacuum），通常(chang)用壓(ya)力值(zhi)表示(shi)。因此(ci)真(zhen)(zhen)空(kong)(kong)包裝(zhuang)實(shi)際(ji)上不是完(wan)全真(zhen)(zhen)空(kong)(kong)的，采用真(zhen)(zhen)空(kong)(kong)包裝(zhuang)技術包裝(zhuang)的食品(pin)容器內的真(zhen)(zhen)空(kong)(kong)度通常(chang)在(zai)600-1333Pa。所以，又(you)將真(zhen)(zhen)空(kong)(kong)包裝(zhuang)稱(cheng)為減壓(ya)包裝(zhuang)或排氣(qi)包裝(zhuang)。