The SSH protocol provides secure communication over an unsecured network, primarily allowing for secure remote login and command execution. It uses encryption methods, ensuring that data transferred between the client and server remains confidential. SSH also supports secure file transfer, port forwarding, and secure tunneling. Its use of public-key cryptography enhances security significantly, as it ensures that both parties involved in the communication can verify each other's identities. Overall, the SSH protocol effectively protects against various threats, such as man-in-the-middle attacks, by encrypting the data exchanged.