Telnet (stands for “teletype network”.) is an application protocol used on the Internet or local area network to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection.
Secure Shell (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Typical applications include remote command-line, login, and remote command execution, but any network service can be secured with SSH.
Can use SSH tools to access hardware and software in a hardware, for example, to access a remote virtual machine.
Some SSH tools: PuTTY; MobaXterm