The Vacuum in "vacuum package" is translated from vacuo in Latin which means nothingness. In fact, the vacuum should be understood that special space with less gas. What we called as "vacuum package" does not refer to space without gas totally, it just means a special package space with gas that less than one atmospheric pressure. In the vacuum state, We call the state of gas lean degree as degree of vacuum. While the vacuum degree of vacuum package is abot 600-1333PA (Standard atmospheric pressure is 101325PA).