Auto login remote server by copying ssh public key to authorized keys

>While working on remote machine we often get headache of entering password for ssh login, scp files from one server to another server. Adding public key as authorized_keys on remote server solves this problem.
Copying from my system to remote server cat ~/.ssh/id_rsa.pub | ssh sandip@server 'cat >> ~/.ssh/authorized_keys'Copying from remote server to my system
ssh server 'cat ~/.ssh/id_rsa.pub' | cat >> ~/.ssh/id_rsa_client.pub