SSH is a deterent to snooping of packet information that travels over the internet.
All information is encrypted before it is sent over the internet.
This means that sensitive information like passwords or confidential information is not a readable format to the snooper. Use of SSH provides additional security for the user. Other operating systems can be found at the above link or via a web search. SSH is Freeware. You will need to Download TeraTerm and the SSH add-on.