SSH enables two computers to establish a secure and direct connection within a potentially unsecure network, such as the internet. This is necessary so that third parties can’t access the data stream, which would result in sensitive data falling into the wrong hands. Even before secure shell, there were ways to establish direct connection between two computers, but the corresponding applications such as Telnet, Remote Shell, or rlogin were all unsecure. SSH encrypts the connection between two computers and enables a second one to be operated from one computer.