Secure Shell (SSH) is a network protocol that provides secure encrypted communications between two untrusted hosts over an insecure network. It is widely used to log into a remote machine and execute commands, but it also supports tunneling, forwarding TCP ports and X11 connections.
SSH provides strong authentication and secure encrypted communications between two untrusted hosts, for example between a client and a server. The protocol consists of two components: the SSH client and the SSH server. The SSH client is used to establish a secure and encrypted connection to the SSH server, while the SSH server provides secure encrypted communications between the client and the server.
SSH is typically used to log into a remote machine and execute commands, but it also supports other services like SFTP (Secure File Transfer Protocol) and SCP (Secure Copy Protocol), which provide secure encrypted file transfer services.
In summary, SSH is an essential tool for network administrators, system administrators and developers for secure remote access to systems and for securely transferring files between systems.