How to SSH between two computers


step 1: install openssh severs and library using the command 
       sudo apt-get install openssh-server openssh-client 

step 2:  start an ssh server 
     sudo systemctl start ssh  #this is for ubuntu 16.04
    sudo service ssh start #other linux systems


SETTING UP THE SERVER (optional)

step 3:  back up the config file in the ssh folder {~/etc/ssh}
    sudo cp /etc/ssh/sshd_config{,.bak}

step 4:open this an editor
 sudo nano /etc/ssh/sshd_config
   leave most of the things in this file. Certain things that can be done using this file is :

• changing the port used for connection
• check on the public and private keys
• change the time for which u can log in