A cryptocurrency hardware wallet is a physical device that keeps your private key safe and away from the prying eyes of criminals while giving the user easy access to their cryptocurrencies.
Typically, users keep their private key on the same computer they use daily, or worse, let exchanges handle their private keys. But computers are susceptible to hacking and malicious software and exchanges are even worse. Moving funds to a hardware wallet with a newly generated key pair will ensure that the stored cryptocurrency is as safe as it can possibly be.
There are several popular hardware wallets, they all perform the same basic functions: Generating a new private key, offline and within the device itself, displaying the corresponding public key to allow coins to be sent to the device, displaying information about what is held on the device and they usually offer an easy way to get cryptocurrencies off the device for spending or sending elsewhere.
The three most popular wallets are KeepKey, Ledger (Nano S) and Trezor. Another product, OpenDime, isn’t technically a hardware wallet because of limited functionality, but it is a cheaper option that has a lot of the same functions. Essentially, it is a one-time use wallet that will allow you to continually add funds but must be physically destroyed to take the funds out.
Deciding what is the best hardware wallet for you comes down to your own needs and what you need.