Ledger is a reputable French company that since 2014 has been manufacturing and selling hardware wallets.
In order to manage cryptocurrencies, you need to have an address - a public key where your, for example, Bitcoin will be stored. With a public key, you also need to own a private key that will allow you to manage your Bitcoins only. They are not on your Legder Nano S wallet. It only stores your private keys. Your Bitcoins are actually the mathematical result of pairing these two keys, and all the information about this is on the blockchain, in the case of Bitcoin, on the Bitcoin blockchain, meaning thousands of computers at once, scattered all over the world.
To make it easier to work with cryptocurrencies, there are various services (crypto wallets) that, with their simple and intuitive interfaces, allow you to manage your cryptocurrencies in an easier and faster way. Using such crypto wallets exposes you to becoming a victim of a hacking attack on that wallet, on your computer, or for the owner, for example, of an exchange office to disappear overnight and take with you all the stored cryptocurrencies of all users.
With the Ledger Nano S hardware wallet, security is first and foremost because your private keys never leave your Ledger Nano S, it is never connected to the Internet, but transaction authentication takes place inside the wallet and communication with the computer is encrypted. The added security of the Ledger Nano S is that the device itself uses a security chip and a specially developed operating system called BOLOS.
Another important aspect of using the Legder Nano S wallet; that is, if you lose, someone steals you or your dog bites your Ledger, for example, nothing is lost. In the instructions for configuring your wallet, you have generated 24 seed words, which are some kind of password, with which you can recreate your account and access all your cryptocurrencies.
A PIN number is used for daily use of Ledger and it is important that you, like other passwords, keep your PINs in a safe place.
Ledger Nano With a hardware wallet, it's safe to manage it from a desktop computer or by connecting to a smartphone, whether it's infected by viruses or other malicious programs. The Nano S model directly enables the operation of 22 cryptocurrencies and more than 1,000 different cryptocurrencies through supported applications (Myetherwallet, Mycrypto…).