What is a public key?

Some web hosts may ask you for a public key before you can upload files or access the server through the SSH and FTP protocols. A public key is one part of a pair of files that are used for authenticating connections. This ensures that you are the only one who can access the sensitive data and functions of your server. Most modern operating systems provide utilities for generating yourself a public key, which you can then send to the web host to upload to their site in the necessary file directory.