Search Results

~/.ssh/known_hosts is used by the client alone, to identify servers the client has connected to before.

~/.ssh/authorized_keys is used by the server being connected to, when you ssh into that user...

The next connection will compare the server's public host key with the one in known_hosts.
If different it will warn "host key changed, perhaps a man-in-the-middle attack".
--
To complete your...

The files in /etc/ssh are for the service on the server you are connecting to. it uses them to listen and exchanges keys with the client session so that the data is encrypted.

Your personal keys...