When it comes to the use of ssh service (client & server), I'm quite confused as to the use of these two files, :
what's the difference between them? what are their similarities (if any)?which one's on the server-side and which one's on client-ssh?
any help is highly appreciated. Thanks in advance.
authorized_keys is a file that allows you to add ssh public keys of users that should be allowed to log into your server (the server in which the authorized_keys file lives) using key based auth.
known_hosts is a file that contains a list of keys from...known hosts that you have logged into. These keys pair an IP address with a server's key to help prevent you from logging into an impersonated server. Usually these keys will be setup the first time you log into a host but you can also manually configure these if security is very critical in your environment.
~/.ssh/ ?