A private key has a few advantages over password. It is much longer than a password, making it exponentially more difficult to brute force. It also eliminates the need to type in a password, making it convenient to connect to remote servers. Passwordless authentication is also helpful for cron jobs and other services that need to run automatically without human intervention. Some servers disable password authentication completely and require a key.
The remote server will need to have your public key as an authorized key before you can authenticate using the private key.
You can use the ssh-copy-id tool if it is available on your system. It will copy your public key to the remote server, place it in your home ...
