真空(kong)(kong)(kong)(kong)，這一(yi)術語譯(yi)自(zi)拉(la)丁文(wen)vacuo，其意義(yi)是虛無。其實(shi)(shi)真空(kong)(kong)(kong)(kong)應理解為(wei)(wei)氣(qi)體較(jiao)稀薄的(de)空(kong)(kong)(kong)(kong)間。在(zai)指(zhi)定的(de)空(kong)(kong)(kong)(kong)間內，低于一(yi)個大氣(qi)壓(ya)力的(de)氣(qi)體狀(zhuang)態(tai)統稱(cheng)為(wei)(wei)真空(kong)(kong)(kong)(kong)。真空(kong)(kong)(kong)(kong)狀(zhuang)態(tai)下(xia)氣(qi)體稀薄程度(du)稱(cheng)為(wei)(wei)真空(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常用(yong)(yong)壓(ya)力值表示。因此真空(kong)(kong)(kong)(kong)包(bao)(bao)(bao)裝(zhuang)(zhuang)(zhuang)(zhuang)實(shi)(shi)際上不是完全真空(kong)(kong)(kong)(kong)的(de)，采用(yong)(yong)真空(kong)(kong)(kong)(kong)包(bao)(bao)(bao)裝(zhuang)(zhuang)(zhuang)(zhuang)技術包(bao)(bao)(bao)裝(zhuang)(zhuang)(zhuang)(zhuang)的(de)食品容器內的(de)真空(kong)(kong)(kong)(kong)度(du)通(tong)常在(zai)600-1333Pa。所以，又將真空(kong)(kong)(kong)(kong)包(bao)(bao)(bao)裝(zhuang)(zhuang)(zhuang)(zhuang)稱(cheng)為(wei)(wei)減壓(ya)包(bao)(bao)(bao)裝(zhuang)(zhuang)(zhuang)(zhuang)或排(pai)氣(qi)包(bao)(bao)(bao)裝(zhuang)(zhuang)(zhuang)(zhuang)。