SSH

SSH, short for Secure Shell, is how people control computers they are not sitting in front of. You open a terminal, connect to a remote machine, and from then on everything you type runs there instead of on your own machine, with the connection encrypted so nobody in between can read it. Almost every server on the internet is administered this way.

It comes up in AI writing because it is how agents are usually given access to a machine they are meant to work on. When a report says an agent was given SSH access to a sandbox, it means the agent could run whatever commands it liked inside that environment, exactly as a human administrator would.