Simply put, Offline Storage refers to devices or systems where cryptocurreny tokens can be kept that are not connected to the internet.
This system is seen by a number of crypto traders to be safe as it secures digital assets from potential breach of Black Hat hackers. One notable Offline Storage is the Cold Wallet. Despite the fact that this type of wallet is not connected to the cloud, a token holder with this storage can still receive funds anytime. However, it would be impossible for one to transfer these funds out. Examples of this include hardware wallets, offline-kept paper wallets, and USB just to mention a few.