SSH
A protocol for securely accessing and controlling a remote computer over a network, used to manage headless home lab servers from any machine.
SSH, or Secure Shell, is a protocol that lets you log into and control a remote computer securely over a network connection.
Why home labs use it
A home lab server runs headless: no monitor, no keyboard, no mouse. SSH is how you interact with it. Once a Raspberry Pi is set up and connected to your network, you open a terminal on any other computer, type the Pi's address, and you are inside it. Every command you run executes on the Pi, not on your own machine.
This means the server can sit in a cupboard, a corner, or anywhere with a network connection, and you manage it from wherever you are on the same network.
How it gets set up
The Raspberry Pi Imager lets you enable SSH and set a username and password before the card is even inserted into the Pi. On first boot, the Pi is immediately accessible over SSH without any additional setup. The Raspberry Pi documentation at raspberrypi.com covers the full process in detail.
Later, SSH access can be secured further with key based authentication, removing the need for a password entirely. Tools like Tailscale also make it possible to access your Pi over SSH from outside your home network without opening ports in your router.