Yesterday when I read a post of HVA asking about which is better when using password or public key to authorize to SSH Server. When I read this post, I remembered that I already activated SSH on my Bluehost account, but I never used it. So I decided to try to open a SSH connection in Bluehost and saw what happened when I used password/public key to authorize myself. When I understand the communicate process, I can find out my own answer for the question above.