In the context of Bitcoin, cold storage means a medium of an offline cryptocurrency wallet.

Cold storage wallets are physical data containers to store cryptocurrencies. They stay offline, without connected to communication networks.

This way the protected cryptocurrency can not be obtained remotely by hackers using attack vectors that come with most digital communication interfaces.

Examples of cold storage wallets:

Printed or handwritten piece of paper

Engraved or handcrafted metal object

Dedicated offline microcomputer

Physical coins with security seal

3D printed plastic object

Handcrafted piece of stone

USB drive

An encrypted NFC Wallet Card

Best solution depends on every use case, most important key factors people must keep in mind:

Physical access control

Potential vulnerabilities

Security features

Compatibility

Reusability

Durability

Mobility

Price

Synonyms of cold storage:

offline wallet, cold wallet, offline storage