A hermetic seal is any type of sealing that makes a given object airtight. The term originally applied to airtight glass containers, but as technology advanced it applied to a larger category of materials, including rubber and plastics.

Is hermetically sealed the same as vacuum sealed?

With vacuum packing, most air is removed from the packaging, after which it is hermetically sealed to maintain the vacuum. This technique protects the contents from oxidation, as well as slowing down the oxidation process.

What is the meaning of the word hermetically sealed?

: in an airtight manner : so as to be completely airtight —usually used in the phrase hermetically sealed They have their digitally alarmed, healthfully air-conditioned, hermetically sealed knotty-pine wine cellars …—