noun
idle state; idle condition
Computing term for a device, process, or system that is powered on but not actively processing tasks.
パソコンがアイドル状態のときに自動でアップデートが始まる。
Updates start automatically when the PC is in an idle state.
待機状態 implies a standby or waiting state, often ready to resume immediately, while アイドル状態 is more about being inactive with no pending tasks.
Compound of アイドル (from English 'idle') and 状態 (state, condition).