Cold storage means keeping your cryptocurrency offline on a device that is not connected to the internet, such as a hardware wallet or paper wallet. This protects your coins from hackers who operate online, though you sacrifice some convenience because you must connect the device to the internet to move your coins.
You could buy a hardware wallet, which looks like a small USB drive, load your Bitcoin onto it, and store it in a safe at home or a safe deposit box. Your coins remain safe there until you want to sell them or send them to someone.
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