真(zhen)空(kong)(kong)(kong)，這一術語譯(yi)自拉丁文(wen)vacuo，其意義是虛無。其實真(zhen)空(kong)(kong)(kong)應(ying)理解為(wei)氣體較稀薄(bo)的空(kong)(kong)(kong)間。在(zai)指定的空(kong)(kong)(kong)間內，低(di)于一個大氣壓力(li)的氣體狀(zhuang)態(tai)(tai)統稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)。真(zhen)空(kong)(kong)(kong)狀(zhuang)態(tai)(tai)下(xia)氣體稀薄(bo)程度稱(cheng)為(wei)真(zhen)空(kong)(kong)(kong)度（degreeofvacuum），通常(chang)用(yong)壓力(li)值(zhi)表示。因此(ci)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)的食品容(rong)器內的真(zhen)空(kong)(kong)(kong)度通常(chang)在(zai)600-1333Pa。所(suo)以，又(you)將(jiang)真(zhen)空(kong)(kong)(kong)包(bao)(bao)裝(zhuang)(zhuang)稱(cheng)為(wei)減(jian)壓包(bao)(bao)裝(zhuang)(zhuang)或排氣包(bao)(bao)裝(zhuang)(zhuang)。