Idle machines
Idle machines are servers that are on ‘standby’. They’re ready to use, but waiting.
Don’t confuse this with downtime. An idle machine is working, it’s just not needed yet. Downtime is when the machines crash, and there are sessions waiting.
Idle machines save your money
During quiet times, you may not need all of your servers running. So they’ll go into idle mode. To save on cost and electricity. But it means you can’t start using them quickly as they are already running, rather than having to set up an entirely new server.